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Меморандум з Oppenheimer Acceleration LLC kpi вт, 02/18/2025 - 17:17

In my recent 2nd generation Google Chromecast teardown, “The Google Chromecast Gen 2 (2015): A Form Factor Redesign with Beefier Wi-Fi, Too,” I noted that I subsequently planned on tearing down the Chromecast Ultra, followed by the 3rd generation Chromecast, chronologically ordered per their respective introduction dates (2016 and 2018).

I’ve subsequently decided to flip-flop that ordering, tackling the 3rd generation Chromecast first, in the interest of grouping together devices with output resolution commonality. All three Chromecast generations, also including 2013’s original version, peak-output 1080p video, although the 3rd generation model also bumped up the frame rate from 30 fps to 60 fps; the Ultra variant you’ll see in the near future conversely did 4K. If you’re wondering why I’m referring to them all in the past tense, by the way, it’s because none of them are in production any longer, although everything but the first-generation Chromecast still gets software updates.

Google also claimed at intro that the Chromecast 3 not only came in new color options:

but was also 15% faster than its predecessor (along with adding support for Dolby Digital Plus and fully integrated Chromecast with Nest smart speakers), although the company was never specific about what “15% faster” meant. Was it only in reference to the already mentioned 1080p60 smoother video-playback option? One might deduce that it also referred to more general UI responsiveness, but if true was this due to faster innate processing—which all users would conceivably experience—or higher wireless network performance, only for those with advanced LANs? Or both? I hope this teardown will help answer these and other questions (like why does Wikipedia list no CPU or memory details for this generation?) to at least a degree.

Generally speaking, I try whenever possible to avoid teardowns of perfectly good hardware that end up being destructive, i.e., leaving the hardware in degraded condition that precludes me from putting it back together afterwards and donating it to someone else. In such cases, I instead strive to focus my attention on already nonfunctional “for parts only” devices sourced from eBay and elsewhere. This time, however, all I could find were still-working eBay options:

although the one I picked was not only inexpensive ($10 plus shipping and sales tax, $16.63 total) but was absent its original packaging:

Here’s a closeup of the micro-USB connector—a legacy approach that’s rapidly being obsoleted by the USB-C successor—at the other end of the USB-A power cable:

And here’s a top view of our patient, as usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes:

Followed by a closeup of the top of the main body:

Same goes for the underside:

That printing on the bottom is quite scuffed at this seeming long-time use point, although I suspect it was already faint from the get-go. In the center are “UL Listed” and HDMI logos, with the phrase “ITE E258392” in-between them. And here’s what it says around the circumference:

Google Model NC2-685
1600 Amphitheater Parkway
Mountain View, CA 94043
CAN ICES-3
(B)NMB-3(B)
IC 10395A-NC26A5
FCC ID A4RNC2-6A5B
Made in Thailand
06041HFADVM445

…whatever (some of, I already get the rest of) that means. And phew!

Here’s the HDMI connector on one end of the cable:

And jumping ahead in time a bit, the other end, entering the partially disassembled body:

Back to where we were before in time, the opposite side of the body showcases, left to right, a hardware reset button (you can also reset via software, if the Chromecast is already activated and mobile device-connected), the aforementioned micro-USB power input and a status LED:

Speaking of sides, you probably already noticed the seam around the circumference of the main body. Also speaking of sides, let’s see if it gets us inside. First off, I used the warmed-up iOpener introduced previously in the Chromecast 2 teardown to heat up the presumed glue holding the two halves together at the seam:

Then I set to work with its iFixit-companion Jimmy:

which got me partly, albeit not completely, to my desired end result, complete with collateral damage in the process:

I suspected that the diminutive dallop of under-case thermal paste I’d encountered with the 2nd-generation Chromecast was more substantially applied this time, to counteract the higher heat output associated with the 3rd-generation unit’s “15% faster” boast. So, I reheated the iOpener, reoriented it on the device, waited some more:

and tried, tried again. Yep, there’s paste inside:

Veni, vidi, vici (albeit, in this case, not particularly swiftly):

My, that’s a lot of (sloppily applied, to boot) glue:

The corresponding paste repository on the inside of the upper-case half is an odd spongy donut-shaped thing. I’ve also scraped away some of the obscuring black paint to reveal the metallic layer beneath it, which presumably acts as a secondary heat sink:

Some rubbing alcohol and a tissue cleaned the blue-green goop off the Faraday cage:

Although subsequently removing the retaining screws on either side of the HDMI cable did nothing to get the cage itself off:

Resigning me to just ripping it off (behavior that, as you’ll soon see, wasn’t a one-time event):

Followed by (most of) the black tape underneath it:

I never actually ever got the HDMI cable detached from the lower-case half, but with the screws removed, I was at least able to disconnect it from the PCB:

enabling me to remove the PCB from the remainder of the case…at least theoretically:

This Chromecast-generation time around, there’s an abundance of thermal paste on both sides:

Even after jamming the Jimmy in the gap in attempting to cut the offending paste in half, I still wasn’t able to separate the PCB from the case, specifically down at the bottom where the micro-USB connector was. The ambient light in the room was starting to get dim and I needed to leave for Mass soon, so I—umm—just gave the PCB a yank, ripping it out of the case:

and quickly snapped the remainder of the photos you’ll see, including the first glimpse of the bottom of the PCB:

When I got back home and reviewed the shots, I was first flummoxed, then horrified, and finally (to this very day, in fact) mortified and embarrassed. And I bet that at least a few of you eagle-eyed readers already know where I’m going with this. What’s that in the bottom left-ish edge of the inside of the back half of the case (with the reset button rubber “spring” to its left and the light guide for the activity LED to its right)? Is that…a still-attached screw? Surrounded by a chunk of PCB?

Yes…yes it is. This dissected device is destined solely for the landfill, “thanks” to my rushed ham-handedness. Sigh:

Guess I might as well get this Faraday cage off too:

And clean off the additional inside paste:

The IC in the upper left is Marvell’s Avastar 88W8887 quad wireless transceiver, supporting 1×1 802.11ac, Bluetooth 4.1, NFC and FM, only some of these functions actually implemented in this design. It’s the same chip used in the 2nd generation Chromecast, so the basis for the “15% faster” claim seemingly doesn’t seemingly source here. Next to it on the right is a SK Hynix H5TC4G63EFR-RDA 4 Gbit LPDDR3-1866 SDRAM. Note too the LED in the lower left corner, and the PCB-embedded antennae on both sides. And, since this PCB is “toast” anyway (yes, note the chunk out of it in the lower right, too), I went ahead and lifted the upper right corner of the cage frame to assure myself (and you) that nothing meaningful was hiding underneath:

Back to the previously seen front side of the PCB:

At far left (with the hardware reset switch below it in the lower left corner…and did I mention yet the missing chunk of PCB to the right of it?), peeking out from the cage frame, is a small, obviously Marvell-sourced, IC labeled as follows (ID, anyone?):

MRVL
G868
952GAX

which I suspect has the same (unknown) function(s) as a similarly (but not identically) labeled chip I’d found in the 2nd-generation Chromecast:

MRVL
G868
524GBD

To its left is the much larger Synaptics MM3006, formerly known as the Marvell 88DE3006 (Synaptics having acquired Marvell’s Multimedia Solutions Business in mid-2017). Again, it’s the same IC as in the 2nd generation Chromecast. And finally, at far right is a Toshiba TC58NVG2S0 4 Gbit NAND flash memory. Same flash memory supplier as before. Same flash memory technology as before. But hey, twice the capacity as before (presumably to provide headroom for the added firmware “support for Dolby Digital Plus and fully integrated Chromecast with Nest smart speakers” mentioned earlier)! So, there’s that…

Aside from a bigger flash memory chip (and, ok, getting rid of the magnet integrated into the Chromecast 2’s HDMI connector), what’s different between the 2nd and 3rd generation Chromecasts, and where does Google’s “15% faster” claim come from? The difference, I suspect, originates with the DRAM. I hadn’t specifically mentioned this in the previous teardown, but the Samsung DRAM found there, while also LPDDR3 in technology and 4 Gbit in capacity, was a “K0” variant reflective of a 1600 MHz speed bin. This time, conversely and as already noted, the DRAM runs at 1866 MHz. My guess is that this uptick also corresponds to a slightly faster speed bin for the Marvell-now-Synaptics application processor. And therein lies, between the two, the modest overall system performance boost.

Agree or disagree, readers? Any other thoughts? Let me know in the comments!

—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

 Related Content

• The Google Chromecast Gen 2 (2015): A Form Factor Redesign with Beefier Wi-Fi, Too
• Google’s Chromecast with Google TV: Car accessory similarity, and a post-teardown resurrection opportunity?
• The Google Chromecast with Google TV: Realizing a resurrection opportunity
• Google’s Chromecast with Google TV: Dissecting the HD edition
• Teardown: Chromecast streams must have gotten crossed

The post The Google Chromecast Gen 3: Gluey and screwy appeared first on EDN.

The Defence Research and Development Organisation (DRDO) of India has been instrumental in advancing indigenous unmanned aerial vehicle (UAV) technologies to meet the diverse operational requirements of the Indian Armed Forces. Among its notable developments is the Trinetra UAV, a cutting-edge drone system designed to enhance surveillance, reconnaissance, and tactical operations.

Design and Development

The Trinetra UAV, aptly named after the Sanskrit term for “Three Eyes,” signifies a comprehensive surveillance capability. This UAV is engineered to be lightweight and highly portable, primarily constructed from advanced composite materials that ensure structural integrity while minimizing weight. Its compact design facilitates rapid deployment across various terrains, making it an invaluable asset for field operations.

One of the standout features of the Trinetra is its Vertical Take-Off and Landing (VTOL) capability. Utilizing a quadcopter configuration, the UAV can ascend and descend vertically, negating the need for traditional runways or launch systems. This attribute is particularly advantageous in confined or rugged environments where conventional take-off and landing are impractical.

Technical Specifications

While specific technical details of the Trinetra UAV remain classified, insights can be drawn from DRDO’s previous UAV projects, such as the Netra series. The Netra V4+, for instance, boasts an operational range of up to 10 kilometers and a flight endurance exceeding 60 minutes at mean sea level. It is equipped with a high-resolution imaging payload featuring a 10x optical zoom, enabling detailed surveillance from significant distances. Additionally, the Netra V4+ can operate at altitudes up to 400 meters Above Ground Level (AGL) and is designed for ease of transport and quick assembly, weighing approximately 6.5 kilograms.

Given the evolutionary nature of DRDO’s UAV development, it is plausible that the Trinetra UAV incorporates similar or enhanced specifications, tailored to meet the specific demands of modern military operations.

Operational Capabilities

The Trinetra UAV is designed to execute a wide array of missions, encompassing intelligence gathering, border surveillance, and tactical support. Its VTOL capability ensures that it can be deployed in diverse environments without the constraints associated with traditional UAV launch and recovery methods.

Equipped with advanced electro-optical and infrared sensors, the Trinetra provides real-time video streaming and high-resolution imagery, facilitating both day and night operations. This dual-sensor setup ensures continuous situational awareness, enabling ground commanders to make informed decisions based on live intelligence.

Autonomous navigation is a cornerstone of the Trinetra’s operational design. The UAV can follow pre-programmed flight paths using waypoint navigation, allowing it to conduct missions with minimal human intervention. In scenarios where communication is disrupted or battery levels are critically low, the Trinetra is programmed to autonomously return to its launch point, ensuring mission continuity and asset recovery.

Recent Developments

In a strategic move to enhance its unmanned capabilities, the Indian Army has placed a significant order for nearly 700 Trinetra drones. This procurement aims to bolster surveillance and reconnaissance operations, particularly in challenging terrains such as the Himalayas. The deployment of these drones is expected to provide real-time intelligence, thereby improving operational efficiency and response times. This acquisition aligns with the broader strategy of integrating advanced indigenous unmanned systems into the armed forces to address contemporary security challenges.

Strategic Implications

The induction of the Trinetra UAV into the Indian Armed Forces signifies a pivotal shift towards embracing indigenous technologies for defense applications. This move not only reduces dependency on foreign systems but also fosters self-reliance in critical defense technologies. The Trinetra’s capabilities are poised to enhance border surveillance, counter-insurgency operations, and disaster management efforts. Its real-time intelligence-gathering prowess is expected to be a force multiplier, providing commanders with actionable insights and facilitating informed decision-making in complex operational environments.

Conclusion

The DRDO’s Trinetra UAV represents a significant advancement in India’s unmanned aerial capabilities. Its blend of cutting-edge technology, autonomous features, and adaptability to diverse mission requirements positions it as a pivotal asset in modern warfare and surveillance. As the Indian Armed Forces continue to integrate such indigenous systems, the Trinetra UAV stands as a testament to India’s commitment to technological innovation and self-reliance in defense.

The post The Rise of DRDO’s Trinetra UAV in India’s Defense Landscape appeared first on ELE Times.

Лекція «Невідомі сторони війни: 36 років журналістського досвіду» від Норіто Кунісуе kpi вт, 02/18/2025 - 14:08

Since gallium nitride (GaN) suppliers have taken various approaches to package types and sizes, leading to fragmentation and a lack of multiple footprint-compatible sources for customers, Infineon Technologies AG of Munich, Germany has launched the high-performance CoolGaN G3 Transistor 100V in RQFN 5x6 package (IGD015S10S1) and 80V in RQFN 3.3x3.3 package (IGE033S08S1)...

Gallium Nitride (GaN) technology plays a crucial role in enabling power electronics to reach the highest levels of performance. However, GaN suppliers have thus far taken different approaches to package types and sizes, leading to fragmentation and lack of multiple footprint-compatible sources for customers. Infineon Technologies AG addresses this challenge by announcing the high-performance gallium nitride CoolGaN G3 Transistor 100 V in RQFN 5×6 package (IGD015S10S1) and 80 V in RQFN 3.3×3.3 package (IGE033S08S1).

“The new devices are compatible with industry-standard silicon MOSFET packages, meeting customer demands for a standardized footprint, easier handling and faster-time-to- market,” said, Dr. Antoine Jalabert, Product Line Head for mid-voltage GaN at Infineon.

The CoolGaN G3 100 V Transistor devices will be available in a 5×6 RQFN package with a typical on-resistance of 1.1 mΩ. Additionally, the 80 V transistor in a 3.3×3.3 RQFN package has a typical resistance of 2.3 mΩ. These transistors offer a footprint that, for the first time, allows for easy multi-sourcing strategies and complementary layouts to Silicon-based designs. The new packages in combination with GaN offer a low-resistance connection and low parasitics, enabling high performance transistor output in a familiar footprint.

Moreover, this chip and package combination allows for high level of robustness in terms of thermal cycling, in addition to improved thermal conductivity, as heat is better distributed and dissipated due to the larger exposed surface area and higher copper density.

The post Infineon introduces CoolGaN G3 Transistor in new Silicon- footprint packages to drive industry-wide standardization appeared first on ELE Times.

India’s unmanned aerial vehicle (UAV) industry is soaring to new heights, fueled by rapid technological advancements, policy support, and increasing demand across diverse sectors. From bolstering national security to revolutionizing precision agriculture and infrastructure monitoring, drones are becoming indispensable assets. As the Indian government pushes for self-reliance under the “Make in India” initiative, domestic UAV manufacturers are stepping up with cutting-edge innovations and indigenous designs. In this evolving landscape, several companies are leading the charge, redefining aerial intelligence and automation. Here’s a look at the top 10 UAV manufacturers shaping India’s drone ecosystem in 2025.

1. ideaForge Technology Limited

Established in 2007, ideaForge is a Mumbai-based UAV manufacturer renowned for designing and developing drones tailored for mapping, security, and surveillance applications. Serving defense forces and various government departments, ideaForge holds a significant position in the Indian drone industry. In July 2023, the company marked a milestone by launching its initial public offering (IPO), underscoring its growth trajectory. At Aero India 2025, ideaForge unveiled four new UAVs: NETRA 5, SWITCH V2, a Tactical UAV concept, and a Logistics UAV concept, each designed to address operational challenges in high-stakes environments.

2. Asteria Aerospace

Asteria Aerospace is a prominent player in the Indian drone industry, focusing on the development of UAVs for diverse applications across defense and industrial sectors. The company offers a range of drone solutions tailored to meet specific operational requirements, emphasizing innovation and reliability in its products.

3. Zen Technologies

Specializing in defense training solutions, Zen Technologies has expanded its portfolio to include UAVs and related systems for military applications. Leveraging its expertise in simulation and training, the company provides comprehensive drone solutions that enhance defense capabilities and operational readiness.

4. Paras Defence and Space Technologies

Paras Defence is engaged in the design, development, and manufacturing of a wide array of defense and space engineering products, including UAVs. Catering to various segments of the Indian defense industry, the company contributes to the nation’s strategic capabilities by delivering advanced drone technologies and solutions.

5. Garuda Aerospace

Based in Chennai, Garuda Aerospace offers drone-based solutions across multiple sectors, including agriculture, infrastructure, and surveillance. The company’s focus on delivering cost-effective and efficient UAV services has positioned it as a key player in the Indian drone ecosystem, addressing diverse industry needs with innovative approaches.

6. Aarav Unmanned Systems

Aarav Unmanned Systems specializes in providing drone solutions for industrial applications such as mining, urban planning, and agriculture. Their UAVs are engineered to deliver high-quality data, facilitating informed decision-making processes and enhancing operational efficiency across various sectors.

7. NewSpace Research & Technologies

Headquartered in Bengaluru, NewSpace Research & Technologies focuses on developing persistent drones for earth observation and communications. Collaborating with Hindustan Aeronautics Limited (HAL), the company is instrumental in projects like the Combat Air Teaming System (CATS) Infinity, a high-altitude pseudo-satellite UAV designed for extended endurance and strategic operations.

8. Throttle Aerospace Systems Pvt Ltd

Throttle Aerospace Systems (TAS), based in Bengaluru, is a leading entity in the Indian drone manufacturing sector. As the first Directorate General of Civil Aviation (DGCA)-approved maker of civil drones and licensed to produce military drones, TAS offers a range of innovative products and solutions aimed at transforming mobility across various industries.

9. Drones Origin Private Limited

Located in Hyderabad, Drones Origin Private Limited specializes in the indigenous design and manufacturing of drone and UAV components. Positioning itself as a one-stop solution for various drone-related needs, including propulsion and custom designs, the company emphasizes self-reliance and aligns with the ‘Make in India’ initiative, contributing to the nation’s growing drone manufacturing industry.

10. IG Drones

IG Drones is recognized as one of the top ‘Made-in-India’ drone manufacturers, contributing significantly to the country’s UAV landscape. The company focuses on delivering innovative drone solutions that cater to various industry requirements, enhancing operational efficiency and productivity.

 

The rapid expansion of India’s UAV industry is a testament to the technological advancements and entrepreneurial spirit driving the sector. These top 10 manufacturers exemplify the country’s commitment to innovation, self-reliance, and the strategic integration of drone technology across multiple domains.

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At NORD DRIVESYSTEMS, our sustainability strategy for 2025 focuses on acting in an environmentally conscious, responsible and integer manner. A cross-divisional team as well as the management and owners are part of the implementation. Besides NORD’s products, it includes four further fields of action.

 “Our sustainability strategy for 2025 is a promise to our customers, to the public and to ourselves to consequently act in an ecological, economic and socially responsible manner”, emphasizes Carolin von Rönne from the area of Process and Organisational Development & Corporate Sustainability Management at NORD DRIVESYSTEMS. The strategy comprises five key aspects:

Products

When it comes to sustainability, our products at NORD are also our top priority. This is because the design, life cycle and application areas have an impact on the environment. The concept of sustainability is therefore already rooted in the product development process. “Drives can be found in many areas of industry, where they consume a large proportion of the energy used,” explains Carolin von Rönne. “With efficient drive solutions such as the IE5+ synchronous motor, we want to make a significant contribution to reducing CO₂ emissions.“ The NORD ECO service furthermore supports companies in finding the most efficient drive solutions for them.

Governance & processes

The sustainability management was introduced at NORD in 2022. Since then, the company has achieved important milestones such as an annual sustainability report according to GRI, environmental certifications and the integration of international structures. The central objective in this field of action is the establishment of an international governance structure and CSRD-compliant reporting for the entire NORD DRIVESYSTEMS Group with 48 subsidiaries in 36 countries because the success of other factors – in

Environment

In order to coordinate structured measures and document them in a legally secure manner, international environmental management is essential for NORD. This is implemented in accordance with ISO14001 for the largest subsidiaries. In addition, the climate balance for Scope 1–3 is determined group-wide. NORD DRIVESYSTEMS Group further aims to reduce its energy consumption and amount of waste as well as increase the share of self-produced electric power and the use of renewable energies. Existing biodiversity areas are to be further expanded.

People

In times of skills shortage, NORD continues to increase its attractiveness as an employer. The company is currently rolling out a global digital learning management system to offer all employees the opportunity for further individual development. Further targeted campaigns and measures are intended to promote diversity among the workforce. “Inclusion, respect for human rights, strengthening our work culture, safety and continuous transfer of knowledge are only some of the topics we would like to promote”, says Carolin von Rönne.

Supply chain

NORD wants to reassure its customers and employees that sustainable production is given high priority both at manufacturing facilities and in the upstream supply chain. Risk analyses and other processes are carried out within the framework of the Germany Act on Corporate Due Diligence Obligations in Supply Chains (LKSG).

The post NORD DRIVESYSTEMS SUSTAINABILITY STRATEGY FOR 2025 appeared first on ELE Times.

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For decades, compute architectures have relied on dynamic random-access memory (DRAM) as their main memory, providing temporary storage from which processing units retrieve data and program code. The high-speed operation, large integration density, cost-effectiveness, and excellent reliability have contributed to the widespread adoption of DRAM technology in many electronic devices.

DRAM bit cell—the element that stores one bit of information—has a very basic structure. It consists of one capacitor (1C) and one transistor (1T) integrated close to the capacitor. While the capacitor’s role is to store a charge, the transistor is used to access the capacitor, either to read how much charge is stored or to store a new charge.

The 1T-1C bit cells are arranged in arrays containing word and bit lines, and the word line is connected to the transistors’ gate, which controls access to the capacitor. The memory state can be read by sensing the stored charge on the capacitor via the bit line.

Over the years, the memory community introduced subsequent generations of DRAM technology, enabled by continuous bit-cell density scaling. Current DRAM chips belong to the ’10-nm class’ (denoted as D1x, D1y, D1z, D1a…), where the half pitches of the active area in the memory cell array range from 19 nm down to 10 nm. However, the AI-driven demand for better performing and larger capacity DRAM is propelling R&D into beyond 10-nm generations.

This requires innovations in capacitors, access transistors, and bit cell architectures. Examples of such innovations are high-aspect ratio pillar capacitors, the move from saddle-shaped (FinFET-based) access transistors to vertical-gate architectures, and the transition from 6F2 to 4F2 cell designs—F being the minimum feature size for a given technology node.

A closer look inside a planar 1T-1C DRAM chip: The peripheral circuit

To enable full functionality of the DRAM chip, several other transistors are needed besides the access transistors. These additional transistors play a role in, for example, the address decoder, sense amplifier, or output buffer function. They are called DRAM peripheral transistors and are traditionally fabricated next to the DRAM memory array area.

Figure 1 The 1T-1C-based DRAM memory array and DRAM peripheral area are shown inside a DRAM chip. Source: imec

DRAM peripheral transistors can be grouped into three main categories. The first category is regular logic transistors: digital switches that are repeatedly turned on and off. The second category is sense amplifiers—analog types of transistors that sense the difference in charge between two-bit cells. A small positive change is amplified into a high voltage (representing a logic 1) and a small negative change into zero voltage (representing a logical 0).

These logical values are then stored in a structure of latches called the row buffer. The sense amplifiers typically reside close to the memory array, consuming a significant area of the DRAM chip. The third category is row decoders: transistors that pass a relatively high bias (typically around 3 V) to the memory element to support the write operation.

To keep pace with the node-to-node improvement of the memory array, the DRAM periphery evolves accordingly in terms of area reduction and performance enhancement. In the longer term, more disruptive solutions may be envisioned that break the traditional ‘2D’ DRAM chip architecture. One option is to fabricate the DRAM periphery on a separate wafer, and bond it to the wafer that contains the memory array, following an approach introduced in 3D NAND.

Toward a single and thermally stable platform optimized for peripheral transistors

The three groups of peripheral transistors come with their own requirements. The regular logic transistors must have good short channel control, high on current (Ion), and low off current (Ioff). With these characteristics, they closely resemble the logic transistors that are part of typical systems-on-chips (SoCs). They also need to enable multiple threshold voltages (Vth) to satisfy different design requirements.

The other two categories have more dissimilar characteristics and do not exist in typical logic SoCs. The analog sense amplifier requires good amplification, benefitting from a low threshold voltage (Vth). In addition, since signals are amplified, the mismatch between two neighboring sense amplifiers must be as low as possible. The ideal sense amplifier, therefore, is a very repeatable transistor with good analog functionality.

Finally, the row decoder is a digital transistor that needs an exceptionally thick gate oxide—compared to an advanced logic node—to sustain the higher bias. This makes the transistor inherently more reliable at the expense of being slower in operation.

Figure 2 Here are the main steps needed to fabricate a transistor for DRAM peripheral applications; the critical modules requiring specific developments are underlined. Source: PSS

In addition to these specific requirements, there are a number of constraints that apply to all peripheral transistors. One critical issue is the thermal stability. In current DRAM process flows with DRAM memory arrays sitting next to the periphery, peripheral transistors are fabricated before DRAM memory elements. The periphery is thus subjected to several thermal treatments imposed by the fabrication of the storage capacitor, access transistor, and memory back-end-of-line.

Peripheral transistors must, therefore, be able to withstand ‘DRAM memory anneal’ temperatures as high as 550-600°C for several hours. Next, the cost-effectiveness of DRAM chips must be preserved, driving the integration choices toward simpler process solutions than what logic flows are generally using.

To keep costs down, the memory industry also favors a single technology platform for various peripheral transistors—despite their individual needs. Additionally, there is a more aggressive requirement for low leakage and low power consumption, which benefits multiple DRAM use cases, especially mobile ones.

The combination of all these specifications makes a direct copy of the standard logic process flow impossible. It requires optimization of specific modules, including the transistors’ gate stack, source/drain junctions, and source/drain metal contacts.

Editor’s Note: This is first part of the article series about the latest advancements in DRAM designs. This part focuses on DRAM basics, peripheral circuits, and the journey toward a single, cost-effective, and thermally stable technology platform optimized for peripheral transistors. The second part will provide a detailed account of DRAM periphery advancements.

Alessio Spessot, technical account director, has been involved in developing advanced CMOS, DRAM, NAND, emerging memory array, and periphery during his stints at Micron, Numonyx, and STMicroelectronics.

Naoto Horiguchi, director of CMOS device technology at imec, has worked at Fujitsu and the University of California Santa Barbara while being involved in advanced CMOS device R&D.

Related Content

• DRAM gets more exotic
• FCRAM 101: Understanding the Basics
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• Winbond’s innovative DRAM design and the legacy of Qimonda
• DRAM technology for SOC designers and—maybe—their customers

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