UNIFORM GROOVE-DEPTHS IN (110)SI ANISOTROPIC ETCHING BY ULTRASONIC-WAVES AND APPLICATION TO ACCELEROMETER FABRICATION

Citation
K. Ohwada et al., UNIFORM GROOVE-DEPTHS IN (110)SI ANISOTROPIC ETCHING BY ULTRASONIC-WAVES AND APPLICATION TO ACCELEROMETER FABRICATION, Sensors and actuators. A, Physical, 50(1-2), 1995, pp. 93-98
Citations number
6
Categorie Soggetti
Engineering, Eletrical & Electronic","Instument & Instrumentation
ISSN journal
09244247
Volume
50
Issue
1-2
Year of publication
1995
Pages
93 - 98
Database
ISI
SICI code
0924-4247(1995)50:1-2<93:UGI(AE>2.0.ZU;2-#
Abstract
The use of ultrasonic waves to obtain uniform groove depth in (110) Si anisotropic etching has been studied. Using dynashock-type ultrasonic waves, the frequency of which is switched between three frequencies a t very short intervals, grooves with uniform depth can be successfully formed with widths of 1-20 mu m independently of pattern width and pa ttern spacing. This technology is applied to the fabrication of an acc elerometer with comb-type narrow-gap electrodes. Comb electrodes with a minimum gap of 3.0 mu m and a height of 58 mu m can be formed unifor mly, although they have different pattern widths and pattern spacings. The capacitance of this device has a high sensitivity to acceleration of 39 pF g(-1). By combining it with an output CV converter and ampli fiers, we have produced a sensor with good full-scale linearity of 0.6 3% over the acceleration range 0 to + 2g.