The sloped-wall SWAMI-A defect-free zero bird's-beak local oxidation process for scaled VLSI technology

• Published in: IEEE transactions on electron devices Vol. 30; no. 11; pp. 1506 - 1511
• Main Authors: Chiu, K.Y., Moll, J.L., Cham, K.M., Jung Lin, Lage, C., Angelos, S., Tillman, R.L.
• Format: Journal Article
• Language: English
• Published: IEEE 01-11-1983
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/T-ED.1983.21329

A new scheme for a Side WAll Masked Isolation (SWAMI) process is presented which takes all the advantages provided by LOCOS without suffering its difficulties. The new SWAMI technology incorporates a sloped silicon sidewall and a thin nitride layer around the island sidewalls such that both intrinsic nitride stress and volume expansion-induced stress are greatly reduced. A defect-free fully recessed zero bird's-beak local oxidation process can be realized by the sloped-wall SWAMI. Fabrication technology and NMOS electrical characteristics will be discussed. Two-dimensional simulation of total reduction in effective channel width for ideal vertical isolation, LOCOS, and SWAMI will also be presented. A SWAMI/CMOS circuit including 60K ROM, 2.5K SRAM, and 100 segments of display driver with 5.13 × 5.22 mm 2 chip size has been successfully fabricated. The results indicate that SWAMI is capable of replacing LOCOS as the isolation technology for submicrometer VLSI circuit fabrication.