A manufacturable dual channel (Si and SiGe) high-k metal gate CMOS technology with multiple oxides for high performance and low power applications

Abstract

Band-gap engineering using SiGe channels to reduce the threshold voltage (V TH ) in p-channel MOSFETs has enabled a simplified gate-first high-κ/metal gate (HKMG) CMOS integration flow. Integrating Silicon-Germanium channels (cSiGe) on silicon wafers for SOC applications has unique challenges like the oxidation rate differential with silicon, defectivity and interface state density in the unoptimized state, and concerns with T inv scalability. In overcoming these challenges, we show that we can leverage the superior mobility, low threshold voltage and NBTI of cSiGe channels in high-performance (HP) and low power (LP) HKMG CMOS logic MOSFETs with multiple oxides utilizing dual channels for nFET and pFET.Introduction:

BTI reliability of high-mobility channel devices: SiGe, Ge and InGaAs

“…This model readily explains (c) the reduced NBTI and the stronger voltage-dependence in SiGe pMOS with thin Si cap. Note: the key voltage-dependence signature is observed also in SiGe data by IBM [8] and GeSn data by NUS [9] with similar gate stacks. [11].…”

Unexpected impact of germanium content in SiGe bulk PMOSFETs

“…4), stems from the lower effective mass of Ge as compared to Si. However, this mobility gain is higher than previously demonstrated in the literature [13,14]. The effective gate length impact can be neglected in long devices as L = 10 lm.…”

SiGe composition and thickness effects on NBTI in replacement metal gate / high-κ technologies

“…While NBTI in Si based devices has been challenging, superior NBTI in SiGe based metal gate (MG) / high-κ (HK) stacks has been widely reported over the last few years [1][2][3]. In Refs.…”