Tsung-Lin Lee

Process-strained Si (PSS) CMOS technology featuring 3D strain engineering

We report the demonstration of a process-strained Si (PSS) CMOS technology using the concept of three-dimensional (3D) strain engineering. Methods of producing PSS include stress engineering of trench isolation, silicide, and cap layer, to improve NMOS and PMOS performance simultaneously. Each of these approaches results in a 5-10% enhancement in the ring oscillator (RO) speed. By taking advantage of preferential 3D strain engineering via one or combining more PSS techniques, CMOS performance can be further improved. PSS is a cost effective technology for meeting CMOS power-performance requirements.

A 25-nm gate-length FinFET transistor module for 32nm node

FinFET is the most promising double-gate transistor architecture [1] to extend scaling over planar device. We present a high-performance and low-power FinFET module at 25 nm gate length. When normalized to the actual fin perimeter, N-FinFET and P-FinFET have 1200 and 915 µA/µm drive current respectively at 100nA/µm leakage under 1V. To our knowledge this is the best FinFET drive current at such scaled gate length. This scaled gate length enables this FinFET transistor for 32nm node insertion. With aggressive fin pitch scaling, the effective transistor width is approximately 1.9X and 2.7X over planar for typical logic and SRAM on the same layout area (i.e., silicon real estate). Due to superior electrostatics and reduced random dopant fluctuation, this high drive current can be readily traded with VDD scaling for low power.

A low operating power FinFET transistor module featuring scaled gate stack and strain engineering for 32/28nm SoC technology

We show that FinFET, a leading transistor architecture candidate of choice for high performance CPU applications [1–3], can also be extended for general purpose SoC applications by proper device optimization. We demonstrate superior, best-in-its-class performance to our knowledge, as well as multi-Vt flexibility for low-operating power (LOP) applications. By high-k/metal-gate (HK/MG) and process flow optimizations, significant drive current (ION) improvement and leakage current (IOFF) reduction have been achieved through equivalent oxide thickness (EOT) scaling and carrier mobility improvement. N-FinFET and P-FinFET achieve, when normalized to Weff (Weff=2xHf+Wf), ION of 1325 µA/µm and 1000 µA/µm at 1 nA/µm leakage current under VDD of 1 V, and 960 uA/um and 690 uA/um at 1 nA/um under Vdd of 0.8V, respectively. This FinFET transistor module is promising for a 32/28nm SoC technology.

28nm metal-gate high-K CMOS SoC technology for high-performance mobile applications

An industry leading 28nm high-performance mobile SoC technology featuring metal-gate/high-k process is presented. The technology is optimized to offer wide power-to-performance transistor dynamic range and highest wired gate density with superior low-R/ELK interconnects, critical for next generation mobile computing/SOC applications. Through process and design optimization, historical trend is maintained for gate density and SRAM cell sizes. Variations control strategy through process and design collaboration is also described.