In-Soo Jung

Performance Boosting of Peripheral Transistor for High Density 4Gb DRAM Technologies by SiGe Selective Epitaxial Growth Technique

The SiGe SD structure in peripheral PMOS area of DRAM was successfully integrated without any degradation of peripheral NMOS properties, which is the first approach to DRAM. The PMOS performance enhancement was found to be more than 40%. The authors suggest the SiGe SD structure as the key solution for the improvement of peripheral PMOS transistor properties in sub-50nm DRAM technology

High performance device utilizing ultra-thick-strained-Si (UTSS) grown on relaxed SiGe

We demonstrate a highly manufacturable substrate-induced strained Si device, which is compatible with the conventional Si bulk process. It utilizes ultra-thick-strained Si (UTSS) layer thicker than 3000 /spl Aring/ and relaxed SiGe layer with low Ge content less than 10%. The UTSS n-MOSFET gives 6 /spl sim/ 12% increase in I/sub on/ according to the gate length without the cost of increase in I/sub off/. In addition, more than 5% increase in I/sub on/ for p-MOSFET can be obtained by hybrid stress of UTSS and SiGe source/drain process. We also emphasize the importance of the ratio of channel resistance (R/sub CH/) to source-drain resistance (R/sub SD/) for performance enhancement.

Front-end-of-line (FEOL) optimization for high-performance, high-reliable strained-Si MOSFETs; from virtual substrate to gate oxidation

Front-end-of-line (FEOL) process parameters including virtual substrate (Si/Si/sub 1-x/Ge/sub x/), shallow-trench-isolation (STI) process, and gate oxidation have strong effects on performance and reliability of strained-Si MOSFETs such as gate oxide integrity (GOI), threshold voltage (V/sub TH/ roll-off, reliability behavior including junction breakdown and device isolation characteristics. It is found that gate oxide integrity can be improved by 1 order of magnitude by applying low-temperature, plasma oxidation process as compared with thermal oxidation, junction leakage and device isolation characteristics can be improved by 1 order of magnitude and by two times, respectively, by using low-defect virtual substrate and further defect-curing process, and parameters related with STI process such as thin SiN layer and oxide densification temperature must be optimized both to reduce junction leakage current and to improve device performance such as Ion-Ioff characteristics.

High performance cell technology featuring sub-100nm DRAM with multi-gigabit density

Fully metal embedded cell technologies, including poly-Si/W/sub x/N/W gate, Co salicide with elevated source/drain using UHV-selective epitaxial growth and CVD-W cell pad has been integrated successfully for the first time for 100 nm design rule DRAM devices. Each key technology exhibits excellent performance.