Search

We have studied the early stages of silicon nitride chemical vapor deposition (CVD) on silicon dioxide using medium energy ion scattering. The growth mode consists of island nucleation followed by coalescence. Similar behavior is observed for films grown using different precursors and reactor environments, indicating that the growth mode is caused by the fundamental nonwetting nature of the nitride/oxide interface under the conditions used for CVD.

This work addresses the design and optimization of high performance CMOS devices in the sub-60 nm regime. Aggressive scaling of the poly gate length is achieved by controlling the short-channel effects in partially-depleted SOI (Silicon-On-Insulator) CMOS devices. In addition, SOI specific design issues are examined to reduce device parasitics such as junction capacitance and history effect through the optimization of silicon film thickness. A high performance SOI CMOS with well-behaved 52 nm gate length devices is demonstrated.

This paper describes a 1.2V high performance 0.13 /spl mu/m generation SOI technology. Aggressive ground-rules and a tungsten damascene local interconnect render the densest 6T SRAM reported to date with a cell area of 2.16 /spl mu/m/sup 2/. This is accomplished with 248nm lithography, using optical proximity correction and resolution enhancement techniques on all critical levels. Interconnect performance requirements are achieved by using up to 8 levels of Cu wiring and an advanced low-k interlevel dielectric.

This paper investigates the implementation of sub-resolution assist features (SRAFs) in high performance logic designs for the poly-gate conductor level. We will discuss the concepts used for SRAF rule generation, SRAF data preparation and what we term "binary" optical proximity correction (OPC) to prevent catastrophic line-width problems. Lithographic process window (PW) data obtained with SRAFs will be compared to PW data obtained without SRAF. SRAM cells are shown printed with annular illumination and SRAFs, for both the 130 nm and 100 nm logic nodes as defined by the International Technology Roadmap for Semiconductors (ITRS). This study includes a comparison of the experimental results of SRAMs printed from designs corrected with rule-based OPC to those printed from designs corrected with model-based OPC.

We present a systematic study on maximizing polysilicon gate activation for aggressively scaled 0.1 /spl mu/m CMOS technologies. The fundamental limit of gate activation due to poly depletion effect was investigated in terms of gate implant/anneal condition and sequence, poly grain size, dopant penetration and activation. For the first time, we achieved significant improvement in CMOS performance by developing a novel process of "gate postdoping" to decouple implant and anneals for gate, source/drain, and extension. The method successfully reduces the poly depletion effect and thus the equivalent gate oxide thickness in inversion by up to /spl sim/2 /spl Aring/, improving CMOS on-currents by 9/spl sim/33% over a conventional process.