Endpoint Detection of Very Deep Sub-Micro (VDSM) Poly Etching Process Based on Complicated Signal Processing

By the analysis of difficulties in VDSM poly gate etching process, firstly, this paper discussed traditional endpoint detection techniques of optical emission spectroscopy (OES) and interferometer endpoint detection (IEP) in detail, then, constructing our innovated endpoint detection system, and based on the complicated signal processing of optical and electrical signal from VDSM poly gate etching process, the endpoint is pre-found precisely. As the experiment of endpoint detection is carried out on sub-90 patterned poly gate substrates, very important guidance to the endpoint detection of sub-90 nm VDSM poly gate etching process may be expected.