Self-Aligned Contact Process Using an Ion-Implanted Silicon Nitride Film As an Oxidation Mask
Original Publication Date: 1984-Jan-01
Included in the Prior Art Database: 2005-Feb-02
This article relates generally to integrated circuit fabrication techniques [*] and more particularly to an integrated circuit fabrication technique which uses ion-implanted nitrogen to form a silicon nitride mask against oxidation in both the unipolar and bipolar device environments. The method includes the following steps: 1. Gate Delineation- Polysilicon gate for a MOSFET is formed using reactive-ion etching (RIE), as shown in Fig. 1A. 2. Nitrogen Implantation- Nitrogen ion is implanted through the gate oxide into the silicon substrate (Fig. 1B). The dose and implant energy is set so that the nitrogen concentration peaks at the silicon-silicon dioxide interface.