AVS 53rd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM-ThP

Paper EM-ThP37
Effects of Additive C@sub 4@F@sub 8@ on Dry Etching of TaN/HfO@sub 2@ Gate Stack Structure using Inductively Coupled BCl@sub 3@/Ar Plasma

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Electronic Materials and Processing Poster Session
Presenter: J.H. Ko, Sungkyunkwan University, Korea
Authors: J.H. Ko, Sungkyunkwan University, Korea
M.S. Park, Sungkyunkwan University, Korea
D.-Y. Kim, Sungkyunkwan University, Korea
S.S. Lee, Hanyang University, Korea
J. Ahn, Hanyang University, Korea
N.-E. Lee, Sungkyunkwan University, Korea
Correspondent: Click to Email
As the advanced nano-scale CMOS (complementary-metal-oxide-semiconductor) device dimensions continue to be scaled down below 50 nm, development of advanced high-k gate dielectrics with metal gate electrodes and their integration has obtained considerable interests. Among many integration issues, selective etching processes of metal gate electrodes over the high-k gate dielectrics and the high-k gate dielectrics over the Si substrate are expected to be the critical steps in the process integration of the front-end of the line (FEOL). In this work, we compared the etching characteristics of the TaN/HfO@sub 2@ gate stack structure and etch rate selectivity of the TaN over the HfO@sub 2@ layer in the BCl@sub 3@/Ar and BCl@sub 3@/C@sub 4@F@sub 8@/Ar plasmas by varying the process parameters such as the top electrode power, the DC self-bias voltage (V@sub dc@), and BCl@sub 3@/C@sub 4@F@sub 8@ gas flow ratio. To understand the role of etch gas chemistry in ICP etching, the relative change in the densities of ions and radicals in the plasma and chemical binding states of etched TaN and HfO@sub 2@ surfaces were measured by optical spectroscopy (OES) and X-ray photoelectron spectroscopy (XPS), respectively. The results of the etch rates and etch selectivity measured as a function of the various process parameters will be discussed in detail in conjunction with the OES and XPS analysis data. Keywords: HfO@sub 2@, TaN, plasma etching, ICP (inductively coupled plasma), metal gate stack.