Chien-Hao Chen

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 Ioff=100 nA/mum, Vdd=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 Ioff ~1 nA/mum @ Vdd = 1V. Low sub-threshold leakage was achieved while successfully containing Iboff and Igoff well below 1 nA/um. Ultra high density 0.15 um2 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.

Effects of germanium and carbon coimplants on phosphorus diffusion in silicon

The authors have studied the interactions between implant defects and phosphorus diffusion in crystalline silicon. Defect engineering enables ultrashallow n+∕p junction formation using phosphorus, carbon, and germanium coimplants, and spike anneal. Their experimental data suggest that the positioning of a preamorphized layer using germanium implants plays an important role in phosphorus diffusion. They find that extending the overlap of germanium preamorphization and carbon profiles results in greater reduction of phosphorus transient-enhanced diffusion by trapping more excess interstitials. This conclusion is consistent with the end-of-range defects calculated by Monte Carlo simulation and annealed carbon profiles.

The influence of nitrogen incorporation on performance and bias temperature instability of metal oxide semiconductor field effect transistors with ultrathin high-k gate stacks

This paper reports a comprehensive study on the influence of nitrogen incorporation on high-k (HK) device performance and reliability. Two approaches including dielectric nitrogen annealing and interfacial layer (IL) nitrogen annealing are investigated. It is found the HK nitrogen annealing is a better solution for the trade-off between mobility and inversion oxide thickness than IL annealing. The positive bias temperature instability characteristic is improved by HK annealing. However, the HK nitrogen annealing lowers the barrier of dielectric and thus results in an abnormally high leakage current.