矽化鉑╱複晶矽接觸電阻之研究

Abstract

本論文旨在探討以傳統離子佈植，離子穿透矽化物 (ITS)，離子穿透金 屬(ITM) 技術所製備之矽化鉑／複晶矽結構的接觸電阻。接觸電阻之測量 係使用六端點卡文(kelvin)測試結構。本論文研究並以掃描式電子顯微 鏡(SEM) 觀測此結構的表面及剖面狀態，以探討其接觸 電阻關連性。 P 型複晶矽中的接觸電阻小於N 型複晶矽的接觸電阻； 而P 型複晶矽中 以離子穿透矽化物方式製備之接觸結構的接觸電阻又小於以離子穿透金屬 方式製備之接觸結構的接觸電阻。若作為工業應用，本論文建議使用離子 穿透矽化物方式製作P 型複晶矽之接觸結構，（二氟化硼離子之佈植量1 E16），退火溫度 750-800℃，或用離子 穿透金屬方式製作 P型複晶矽 之接觸結構，（二氟化硼離子之佈植量 1E16），退火溫度 650-800℃。 The thesis studies the contact resistivity of the Ptsi/ p+- polysilicon and PtSi/n+-polysilicon contact structures fabricated by conventional, implant-through-silicide (ITS), and implant-through-mental（ITM）techniques. The contact resistivity is determined by using the six-terminal CBKR test structure. The effect of implanted impurity （BF2+ and As+ ） dose on the contact resistivity is investigated. The contact resistivity is also studied with respect to the process temperature of the contact test structure. In addition, SEM inspection was used to examine the PtSi surface and the PtSi／ polysilion interface morphology which is correlated to the contact degradation. It is found that the contact resistivity of the PtSi／P+-polysilicon contact structure is lower than that of the PtSi／n+-polysilicon contact structure, while the contact resistivity of the ITS processed samples is lower than that of the ITM processed ones with BF2+ implantation.For the PtSi/polysilicon contact structure, good ohmic contact can be obtained by using the ITS and ITM techniques.For practical application, the following ITS/ITM process condition is proposed for a structure with Pt thickness of 300o or PtSi thickness of 600o; BF2+ implantation at 100keV to a dose of 1E16, annealing temperature 750 to 800℃ for the ITS scheme, and 650 to 800℃ for the ITM scheme.