IEDM 2017 Preview

The 63rd annual IEDM (International Electron Devices Meeting) will be held December 2nd through 6th in San Francisco. In my opinion IEDM is one of, if not the premier conference on leading edge semiconductor technology. I will be attending the conference again this year and providing coverage for SemiWiki. As a member of the press I got some preview materials today and I wanted to share some of it with you.

Leading Edge Logic
As anyone who has read my articles on SemiWiki knows I follow the latest advances in logic process technology very closely. In the Platform Technology Session there will be papers from Intel on their 10nm technology and GLOBALFOUNDRIES on their 7nm technology and I am really looking forward to these papers:

• Intel: Intel researchers will present a 10nm logic technology platform with excellent transistor and interconnect performance and aggressive design-rule scaling. They demonstrated its versatility by building a 204Mb SRAM having three different types of memory cells: a high-density 0.0312µm[SUP]2[/SUP] cell, a low voltage 0.0367µm[SUP]2[/SUP] cell, and a high-performance 0.0441µm[SUP]2[/SUP] cell. The platform features 3[SUP]rd[/SUP]-generation FinFETs fabricated with self-aligned quadruple patterning (SAQP) for critical layers, leading to a 7nm fin width at a 34nm pitch, and a 46nm fin height; a 5[SUP]th[/SUP]-generation high-k metal gate; and 7[SUP]th[/SUP]-generation strained silicon. There are 12 metal layers of interconnect, with cobalt wires in the lowest two layers that yield a 5-10x improvement in electromigration and a 2x reduction in via resistance. NMOS and PMOS current is 71% and 35% greater, respectively, compared to 14nm FinFET transistors. Metal stacks with four or six workfunctions enable operation at different threshold voltages, and novel self-aligned gate contacts over active gates are employed. (Paper 29.1, “A 10nm High Performance and Low-Power CMOS Technology Featuring 3[SUP]rd[/SUP]-Generation FinFET Transistors, Self-Aligned Quad Patterning, Contact Over Active Gate and Cobalt Local Interconnects,” C. Auth et al, Intel)
• GLOBALFOUNDRIES (GF): GF researchers will present a fully integrated 7nm CMOS platform that provides significant density scaling and performance improvements over 14nm. It features a 3[SUP]rd[/SUP]-generation FinFET architecture with SAQP used for fin formation, and self-aligned double patterning for metallization. The 7nm platform features an improvement of 2.8x in routed logic density, along with impressive performance/power responses versus 14nm: a >40% performance increase at a fixed power, or alternatively a power reduction of >55% at a fixed frequency. The researchers demonstrated the platform by using it to build an incredibly small 0.0269µm[SUP]2[/SUP] SRAM cell. Multiple Cu/low-k BEOL stacks are possible for a range of system-on-chip (SoC) applications, and a unique multi-workfunction process makes possible a range of threshold voltages for diverse applications. A complete set of foundation and complex IP (intellectual property) is available in this advanced CMOS platform for both high-performance computing and mobile applications. (Paper 29.5, “A 7nm CMOS Technology Platform for Mobile and High-Performance Compute Applications,”S. Narasimha et al, Globalfoundries)

Silicon Photonics
Silicon Photonics is an area of great interest in the industry today and in my cost modeling business I am getting a lot of interest in Silicon Photonics costs. Session 34 will focus on Silicon Photonics.

Silicon Photonics: Current Status and Perspectives (Session #34) – Silicon photonics integrated circuits consist of devices such as optical transceivers, modulators, phase shifters and couplers, operating at >50 GHz for use in next-generation data centers. This session describes the latest in photonics IC advances in state-of-the-art 300mm fabrication technology; integrated nano-photonic crystals with fJ/bit optical links; and advanced packaging concepts for the specialized form factors this technology requires.

• “Developments in 300mm Silicon Photonics Using Traditional CMOS Fabrication Methods and Materials,” by Charles Baudot et al, STMicroelectronics
• “Reliable 50Gb/s Silicon Photonics Platform for Next-Generation Data Center Optical Interconnects,” by Philippe Absil et al, Imec
• “Advanced Silicon Photonics Technology Platform Leveraging the Semiconductor Supply Chain,” by Peter De Dobbelaere, Luxtera
• “Femtojoule-per-Bit Integrated Nanophotonics and Challenge for Optical Computation,” by Masaya Notomi et al, NTT Corporation
• “Advanced Devices and Packaging of Si-Photonics-Based Optical Transceiver for Optical Interconnection,” by K. Kurata et al, Photonics Electronics Technology Research Association

Nanowires
With FinFETs coming to the end of it’s scaling potential nanowires are garnering a lot of interest as the next generation technology. In session 37 there will be a couple of papers on nanowires incuding:

First Circuit Built With Stacked Si Nanowire Transistors: As scaling continues, gate-all-around MOSFETs are seen as a promising alternative to FinFETs. They are nanoscale devices in which the gate is completely wrapped around a nanowire, which serves as the transistor channel. Nanosheets, meanwhile, are sheets of arrays of GAA nanowires. A talk by Imec and Applied Materials will describe great progress in several key areas to make vertically stacked GAA nanowire and/or nanosheet MOSFETs practical. The team built the first functional ring oscillator test circuits ever demonstrated using stacked Si nanowire FETs, with devices that featured in-situ doped source/drain structures and dual-workfunction metal gates. An SiN STI liner was used to suppress oxidation-induced fin deformation and improve shape control; a high-selectivity etch was used for nanowire/nanosheet release and inner spacer cavity formation with no silicon reflow; and a new metallization process for n-type devices led to greater tunability of threshold voltage. (Paper 37.4, “Vertically Stacked Gate-All-Around Si Nanowire Transistors: Key Process Optimizations and Ring Oscillator Demonstration,” H. Mertens et al, Imec/Applied Materials)

Conclusion
These papers are just a sampling of what will be presented that are of interest to me. I highly recommend attending IEDM for anyone interested in staying current on the state-of-the art.

https://ieee-iedm.org/