The porous silicon film, at micron level, and the bulk silicon substrate is a basic structure in MEMS components. The residual stress, due to the lattice mismatch between the film and the substrate, exists on the interface and may cause cracking and damaging on the component. Micro-Raman spectroscopy is an optical measurement method that was rapidly applied into the fields of chemistry, physics, material science and mechanics. In this paper, the method is introduced and applied to the study of the stress problems in porous silicon as follows. (1) In the electrochemical etching technique for porous silicon preparation, the distribution of the tensile residual stress along the transitional region between etched and un-etched area is experimentally studied and the result reveals the stress is continuous across the region. In the etched region it reaches GPa level, and in the transition region the gradient of the stress is high. (2) In chemical etching preparation of porous silicon, the residual stress rises up seriously in the cracked area, up to 0.92 GPa. With the porosity increasing, the tensile stress on the porous silicon film increases accordingly. The appearance of the porous silicon film surface is also given by metalloscope and atomic force microscope. The structure of the micro-pores is expected to have a close relation with the distribution of the residual stress.
[1]
I. Wolf.
Micro-Raman spectroscopy to study local mechanical stress in silicon integrated circuits
,
1996
.
[2]
Qian Jin,et al.
RESIDUAL STRESSES IN MICRO-ELECTRO-MECHANICAL SYSTEMS
,
2001
.
[3]
A. Nassiopoulou,et al.
Stress effect on suspended polycrystalline silicon membranes fabricated by micromachining of porous silicon
,
1998
.
[4]
M. Cardona,et al.
Piezo-Raman measurements and anharmonic parameters in silicon and diamond.
,
1990,
Physical review. B, Condensed matter.
[5]
Fulong Dai,et al.
Study of residual stress in surface nanostructured AISI 316L stainless steel using two mechanical methods
,
2003
.
[6]
Ingrid De Wolf,et al.
Stress measurements in Si microelectronics devices using Raman spectroscopy
,
1999
.
[7]
J. M. Martínez-Duart,et al.
Lattice-mismatch induced-stress in porous silicon films
,
2001
.
[8]
W. V. Spengen,et al.
The investigation of microsystems using Raman spectroscopy
,
2001
.