Highly selective oxide to nitride etch processes on BPSG/nitride/oxide structures in a MERIE etcher

Author

Graf, W. ; Basso, D. ; Gautier, F. ; Martin, J.M. ; Sabouret, E. ; Skinner, G.

Author_Institution

Siemens, Corebil-Essonnes, France

fYear

1998

fDate

23-25 Sep 1998

Firstpage

314

Lastpage

319

Abstract

This study is on oxide etch selective to nitride using a C₄F₈-CO-Ar-O₂ chemistry in a RIE chamber. It has been tested in a manufacturing environment on several applications for 16 and 64 megabit DRAM chips. Film stacks tested included a BPSG/nitride self-aligned contact type of application and a BPSG/nitride/oxide application. Aspect ratios ranged from 4:1 to 8:1. Critical dimensions were typically 0.4 μm and 0.3 μm, but for one application, oxide etch had to finally occur in a 0.09 μm wide space. Process development started with a design of experiments on patterned wafers in order to understand the major trends of the chemistry. The wafers were analysed by SEM. Fine tuning of processes for each application involved optical emission spectroscopy (OES) and electrical test yield analysis

Keywords

DRAM chips; borosilicate glasses; design of experiments; dielectric thin films; integrated circuit design; integrated circuit testing; integrated circuit yield; interface structure; luminescence; phosphosilicate glasses; scanning electron microscopy; silicon compounds; sputter etching; 0.09 micron; 0.3 micron; 0.4 micron; 16 Mbit; 64 Mbit; B2O3-P2O5-SiO2-Si3N4-SiO2; BPSG-Si₃N₄-SiO₂; BPSG/nitride self-aligned contact; BPSG/nitride/oxide application; BPSG/nitride/oxide structures; CO-Ar-O₂; DRAM chips; MERIE etcher; RIE chamber; SEM; aspect ratios; critical dimensions; design of experiments; electrical test yield analysis; film stacks; fluorocarbon-CO-Ar-O₂ chemistry; highly selective oxide to nitride etch processes; manufacturing environment; optical emission spectroscopy; oxide etch; oxide etch selective; patterned wafers; process development; Argon; Etching; Inductors; Plasma applications; Plasma chemistry; Plasma temperature; Polymer films; Silicon; Stimulated emission; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Advanced Semiconductor Manufacturing Conference and Workshop, 1998. 1998 IEEE/SEMI

Conference_Location

Boston, MA

ISSN

1078-8743

Print_ISBN

0-7803-4380-8

Type

conf

DOI

10.1109/ASMC.1998.731580

Filename

731580