Journal of the Institute of Electronics Engineers of Korea SD (대한전자공학회논문지SD)

The Institute of Electronics and Information Engineers (대한전자공학회)
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A Study on sub 0.1$\mu\textrm{m}$ ULSI Device Quality Using Novel Titanium Silicide Formation Process & STI

새로운 티타늅 실리사이드 형성공정과 STI를 이용한 서브 0,1$\mu\textrm{m}$ ULSI급 소자의 특성연구

  • 엄금용 (성남기능대학 광전자과) ;
  • 오환술 (건국대학교 전자·정보통신 공학과)
  • Published : 2002.05.01
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Abstract

Deep sub-micron bulk CMOS circuits require gate electrode materials such as metal silicide and titanium silicide for gate oxides. Many authors have conducted research to improve the quality of the sub-micron gate oxide. However, few have reported on the electrical quality and reliability of an ultra-thin gate. In this paper, we will recommend a novel shallow trench isolation structure and a two-step TiS $i_2$ formation process to improve the corner metal oxide semiconductor field-effect transistor (MOSFET) for sub-0.1${\mu}{\textrm}{m}$ VLSI devices. Differently from using normal LOCOS technology, deep sub-micron CMOS devices using the novel shallow trench isolation (STI) technology have unique "inverse narrow-channel effects" when the channel width of the device is scaled down. The titanium silicide process has problems because fluorine contamination caused by the gate sidewall etching inhibits the silicide reaction and accelerates agglomeration. To resolve these Problems, we developed a novel two-step deposited silicide process. The key point of this process is the deposition and subsequent removal of titanium before the titanium silicide process. It was found by using focused ion beam transmission electron microscopy that the STI structure improved the narrow channel effect and reduced the junction leakage current and threshold voltage at the edge of the channel. In terms of transistor characteristics, we also obtained a low gate voltage variation and a low trap density, saturation current, some more to be large transconductance at the channel for sub-0.1${\mu}{\textrm}{m}$ VLSI devices.

Keywords

References

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