Integrated stress and process calibration in strained-si devices
We present a novel calibration methodology that (i) integrates dopant diffusion, mechanical strain and bandgap narrowing for accurate device short channel effect modeling and (ii) deploys stress dependent mobility model for robust device performance projection especially on effective drive current (Ideff). Good agreement is obtained between the model calibration and experimental measurements over the full gate length range examined. Moreover, a general mobility gain with respect to uniaxial stress is presented.Series resistance and mobility extraction method in nanoscale MOSFETs
This paper presents a BSIM-based method for source/drain series resistance and mobility extraction in nanoscale strained-silicon metal oxide semiconductor field effect transistors (MOSFETs) with halo implants. This method is more accurate than the conventional channel-resistance and shift and ratio method because it considers the gate-length dependence of mobility caused by local uniaxial stress and laterally nonuniform channel doping. We have verified this method using samples with different stressor/doping conditions and good agreement with experimental data has been obtained. The accuracy of the Berkeley Short-channel IGFET model (BSIM) extraction method is also proven by simulated current–voltage characteristics with different external resistant values. Significant mobility degradation in the short-channel regime has been observed for various uniaxial stressors. This method may serve as a suitable process monitor tool for ultrashallow junction and strained process development.A millisecond-anneal-assisted selective fully silicided (FUSI) gate process
We demonstrate, for the first time, an integration-friendly selective PMOSFET fully silicided (FUSI) gate process. In this process, a millisecond-anneal (MSA) technique is utilized for the nickel silicide phase transformation. A highly tensile FUSI gate electrode is created and hence exerts compressive stress in the underlying channel. The highly flexible integration scheme successfully, and exclusively, implements uniform P + FUSI gates for PMOSFETs while preserving a FUSI-free N + poly-Si gate for NMOSFETs with the feature size down to 30 nm. A 20% improvement in FUSI- gated PMOSFET I on - I off is measured, which can be attributed to the enhanced hole mobility and the elimination of P + poly-gate depletion.32nm gate-first high-k/metal-gate technology for high performance low power Applications
A 32 nm gate-first high-k/metal-gate technology is demonstrated with the strongest performance reported to date to the best of our knowledge. Drive currents of 1340/940 muA/mum (n/p) are achieved at I off =100 nA/mum, V dd =1 V, 30 nm physical gate length and 130 nm gate pitch. This technology also provides a high-Vt solution for high-performance low-power applications with its high drive currents of 1020/700 muA/mum (n/p) at total I off ~1 nA/mum @ V dd = 1V. Low sub-threshold leakage was achieved while successfully containing I boff and I goff well below 1 nA/um. Ultra high density 0.15 um 2 SRAM cell is fabricated by high NA 193 nm immersion lithography. Functional 2 Mb SRAM test-chip in 32 nm design rule has been demonstrated with a controllable manufacturing window.Modeling and characterization of advanced phosphorus ultra shallow junction using germanium and carbon coimplants
A continuum model of phosphorus diffusion with germanium and carbon coimplant has been proposed and calibrated based on secondary ion mass spectroscopy (SIMS) profiles aiming at ultra shallow junction (USJ) formation in advanced CMOS technologies. The phosphorus diffusion behaviors are well captured by our model under various implant and annealing conditions, representing a significant step towards advanced n-type USJ formation technique using phosphorus and carbon coimplant for aggressively scaled CMOS technologies.45nm high-k/metal-gate CMOS technology for GPU/NPU applications with highest PFET performance
Highest planar HK/MG PFET performance (I ON = 790 muA at I off = 100 nA, Vdd= 1 V and Lg= 33 nm) has been demonstrated with a gate-first dual-metal CMOS integrated process and proven by functional SRAM cell. Integrating modern stressors without IL re-growth and achieving band edge work function without increasing T INV are two major challenges for gate-first HK/MG processes. In this work, band-edge effective work function has been achieved without increasing T INV . Furthermore, with successful integration of stress techniques like SiGe-S/D, SMT and CESL, not only performance was improved by 30% but also no reliability degradation was observed. Finally, no degradation from decreasing poly-pitch also suggests its good scalability to next generations.A 32nm CMOS low power SoC platform technology for foundry applications with functional high density SRAM
For the first time, we present a state-of-the-art 32 nm low power foundry technology integrated with 0.15um 2 6-T high density SRAM, low standby transistors, analog/RF functions and Cu/low-k interconnect for mobile SoC applications. To our knowledge, this is the smallest fully functional 2Mb SRAM test-chip for 32nm node. Low power transistors with Lg of 30nm achieve current drive of 700/380 uA/um at 1.1V and off-leakage current of 1 nA/um for NMOS and PMOS, respectively. An NPoly/NWell MOS varactor shows capacitance ratio of >5.0. The MOM unit capacitance of 3.5 fF/um 2 is achieved with only 4 metal layers.A highly scaled, high performance 45nm bulk logic CMOS technology with 0.242 μm2 SRAM cell
A highly scaled, high performance 45 nm CMOS technology utilizing extensive immersion lithography to achieve the industry's highest scaling factor with ELK (k=2.55) BEOL is presented. A record gate density 2.4X higher than that of 65 nm is achieved. Refined strained-CMOS demonstrated 1200/750 μA/μm Idsat at 100 nA/μm Ioff, Vdd=1 V, which has the best Ion-Lg performance reported for bulk CMOS device. The proposed 45 nm technology is not only manufacturing friendly but also has well-controlled leakage and mismatch evidenced by a functional 32 Mb 0.242 μm 2 SRAM.Mobility enhancement and strain integration in advanced CMOS
Mobility enhancement techniques have become pervasive in advanced CMOS technologies. Non-scalable and scalable approaches to mobility enhancement are widely used in various application segments (high-speed, low-operating power, and low- standby power). Non-scalable techniques rely on preferential channel directions having fundamentally higher carrier mobility than the conventional <110> directions of (100) substrates. On the other hand, scalable techniques rely on process built-in mechanical strain to boost mobility as a result of band- structure response impacting both carrier-effective mass and scattering rates. Scalable techniques are based on the channel strain induced by contact-etch stop layers or Si(1-x)Ge(x) structures primarily. This paper will review both non-scalable and scalable mobility enhancement approaches from two angles, namely fundamental device physics and overall device integration schemes. The paper will also review and discuss issues related to superposition of process built-in strain for performance enhancement.A new series resistance and mobility extraction method by BSIM model for nano-scale MOSFETs
In this work, a simplified BSIM-based model has been proposed to solve the above issues contributed by halo implants [Goto, K, et al., 2003]. In this new methodology, R sd and mu eff can be uniquely extracted in nano-scale devices. Furthermore, the extracted L G dependency of mu eff may serve as a good indicator for monitoring the relationship between geometry and stress parameters
Logic
Transistor Structure
TSMC CMOS logic technology relied on planar transistor structures until 2014, when FinFETs were introduced into production with our 16nm technology. The FinFET structure resolved a fundamental limitation of planar device scaling, namely the poor electrostatic control of the channel at short gate lengths. FinFETs also enabled a partial decoupling of the transistor density scaling from device effective width scaling, which is an important feature for attaining increased transistor current per unit footprint of transistors. These FinFET characteristics enabled significant reduction of the power supply voltage as compared to planar transistors. FinFET also presents new degrees of freedom for power performance optimization, which contributed to significant enhancements in energy efficiency from 16nm to our most recently introduced 5nm technology node.
TSMC research and development continues to explore next-generation structures such as stacked nanowires or stacked nanosheets in our quest for new heights in computing performance and energy efficiency for future technology nodes.