Silicon acoustic lens for scanning acoustic microscope (SAM)

Author

Hashimoto, H. ; Tanaka, S. ; Sato, K.

Author_Institution

Hitachi Constr. Machinery Co., Ibaraki, Japan

fYear

1991

Firstpage

853

Lastpage

859

Abstract

A single crystal silicon lens for a scanning acoustic microscope (SAM) has been developed by using lithography and chemical etching. Excellent sphericity and the minimal surface roughness demanded for a lens profile have been obtained through suitable etching. The optimum etchant conditions are with hydrofluoric, nitric, and acetic acids in the ratio of 2:3:3 at 50 degrees C. A silicon lens designed specifically for a frequency of 600 MHz has been successfully achieved with a resolution 1.8 microns expected from the wavelength. The influence of the aperture diameter of the etching mask and etching time on the concave profile was clarified. The etched concave profile for a 1 GHz range lens showed a maximum deviation from a perfect sphere of less than 0.2 microns.<>

Keywords

acoustic imaging; acoustic microscopes; acoustic microwave devices; elemental semiconductors; etching; lenses; semiconductor technology; silicon; 1 GHz; 50 degC; 600 MHz; HF; HNO/sub 3/; IC; NDT; Si; acetic acids; chemical etching; concave profile; etching mask; etching time; lens profile; lithography; scanning acoustic microscope; sphericity; surface roughness; Chemicals; Etching; Frequency; Lenses; Lithography; Microscopy; Optical design; Rough surfaces; Silicon; Surface roughness;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensors and Actuators, 1991. Digest of Technical Papers, TRANSDUCERS '91., 1991 International Conference on

Conference_Location

San Francisco, CA, USA

Print_ISBN

0-87942-585-7

Type

conf

DOI

10.1109/SENSOR.1991.149019

Filename

149019