O. Muller et R. Joeckle, MORPHOLOGICAL AND ELECTRICAL MODIFICATIONS IN SILICON SUBMITTED TO HIGH-INTENSITY LASER IRRADIATION, Materials science & engineering. A, Structural materials: properties, microstructure and processing, 168(1), 1993, pp. 81-86
In an effort to study the nature of the damage processes which occur w
hen detectors for visible light are irradiated with high-power laser b
eams, bulk (111) n-type (P doped) silicon samples were submitted to hi
gh intensity 580 nm dye laser pulses for microsecond duration and the
induced morphological (cracks, melting) as well as electrical (sheet r
esistance) modifications were investigated. The irradiation was either
in a variable diameter focused mode, or a uniform power density beam.
The uniform illumination mode allows one to obtain more precise value
s for the morphological degradation occurring with increasing fluence:
from the first appearance of a white coating (over 1.7 J cm-2) to the
progressive formation of cracks (from 5.5 J cm-2 to melting) before m
elting occurs (at 10.7 J cm-2). A detailed study of the resistivity as
a function of fluence is reported, using the latter optical regime, a
nd it is shown that melting is accompanied by a strong increase in she
et resistance (from 50 to 180 kOMEGA).