DPRM工艺中刻蚀工艺关键参数对N/P型MOS管交界处的影响

Influence of Key Parameters of Etching Process on N/P MOS Boundary in DPRM Process

短沟道效应对器件性能的影响不可忽略,高k/金属栅极(High-k/Metal Gate,HKMG)器件可以很好地抑制短沟道效应。HKMG器件中金属栅极的制备工艺有前栅极制造工艺和后栅极制造工艺,其中虚拟栅去除(Dummy Poly Removal,DPRM)过程是后栅极制造中一道至关重要的制程。由于P型MOS管和N型MOS管的金属栅极填充材料不同,制造工艺中要先完成一种MOS管金属栅极的制作再进行另一种MOS管金属栅极的制作,DPRM后N型MOS管和P型MOS管交界处的结构形貌会直接影响金属栅极的填充,进而影响器件性能。在电子回旋共振刻蚀等离子体源条件下,探究DPRM工艺中过刻蚀过程的关键参数对NMOS管和PMOS管交界处结构形貌的影响,进而总结出减弱N/P型MOS管交界处侧向凹陷程度的工艺条件。

The influence of short channel effect on device performance is non-negligible,and high-k/metal gate(HKMG)devices can suppress the short channel effect very well.As is well known,both gate-first and gate-last processes can form metal gates,and dummy poly removal (DPRM)is a critical technique in gate-last method.Due to the different metal materials filled in PMOS and NMOS devices,one type of MOS metal gate electrode shall be completed in the manufacturing process before the other type of MOS metal gate electrode being fabricated.It is worth knowing that the profile of N/P MOS boundary after DPRM will directly affect the filling of metal electrodes,and then affect the device performance.In this work,influence of key parameters in an over-etch step of DPRM process on the profile of N/P MOS boundaryis investigated,which is under the condition of electron cyclotron resonance(ECR)etch plasma source.Then condition of weakening the poly lateral recess(PLR)at the N/P boundary will be summarized .