Etching Simulation of Nonplanar Layers in the Sample Program

S.F. Meier

EECS Department
University of California, Berkeley
Technical Report No. UCB/ERL M87/41
June 1987

http://www2.eecs.berkeley.edu/Pubs/TechRpts/1987/ERL-87-41.pdf

The etching machine of the SAMPLE program has been extended to simulate etching with multiple nonplanar layers. Any arbitrary profile can be entered for each material layer in a device structure. Layer location of profile points is determined using an intersection searching algorithm. The algorithm traverses the top profile structure analyzing the layer boundaries for intersection points at each step. Intersection points are determined by locating candidate segments within range and classifying them into cases for analysis. Cases are analyzed through calculation of z intercepts of segment endpoints with their opposing segments. The intersection algorithm can detect multiple segment intersection and can handle undercutting layer profiles. Monotonic profiles are detected and used to bound the segment search. This new simulation capability allows analysis of several important process sequences. Spin-on and etch-back planarization is simulated using different matching of material etching rates. An oxide spacer sequence is simulated using the capabilities of the etching machine to perform multiple cycle deposition and etching steps. A high resolution metal lift-off process is simulated and used to demonstrate the ability to simulate undercutting profiles.

BibTeX citation:

@techreport{Meier:M87/41,
    Author = {Meier, S.F.},
    Title = {Etching Simulation of Nonplanar Layers in the Sample Program},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {1987},
    Month = {Jun},
    URL = {http://www2.eecs.berkeley.edu/Pubs/TechRpts/1987/901.html},
    Number = {UCB/ERL M87/41},
    Abstract = {The etching machine of the SAMPLE program has been extended to
simulate etching with multiple nonplanar layers. Any arbitrary 
profile can be entered for each material layer in a device
structure. Layer location of profile points is determined using an
intersection searching algorithm. The algorithm traverses the top
profile structure analyzing the layer boundaries for intersection
points at each step. Intersection points are determined by locating
candidate segments within range and classifying them into cases for
analysis. Cases are analyzed through calculation of z intercepts of
segment endpoints with their opposing segments. The intersection
algorithm can detect multiple segment intersection and can handle
undercutting layer profiles. Monotonic profiles are detected and
used to bound the segment search. This new simulation capability
allows analysis of several important process sequences. Spin-on
and etch-back planarization is simulated using different matching
of material etching rates. An oxide spacer sequence is simulated
using the capabilities of the etching machine to perform multiple
cycle deposition and etching steps. A high resolution metal lift-off
process is simulated and used to demonstrate the ability to simulate
undercutting profiles.}
}

EndNote citation:

%0 Report
%A Meier, S.F.
%T Etching Simulation of Nonplanar Layers in the Sample Program
%I EECS Department, University of California, Berkeley
%D 1987
%@ UCB/ERL M87/41
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/1987/901.html
%F Meier:M87/41