Title :
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
Abstract :
This study is on oxide etch selective to nitride using a C4 F8-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;
Conference_Titel :
Advanced Semiconductor Manufacturing Conference and Workshop, 1998. 1998 IEEE/SEMI
Conference_Location :
Boston, MA
Print_ISBN :
0-7803-4380-8
DOI :
10.1109/ASMC.1998.731580
