Title :
A miniaturized thin-film germanium strain gauge
Author :
Khakifirooz, A. ; Mohajerzadeh, S.S. ; Shafiiha, R.
Author_Institution :
Dept. of Electr. & Comput. Eng., Tehran Univ., Iran
Abstract :
A miniaturized thin-film germanium strain gauge suitable for batch fabrication is reported. Lithography is used to pattern individual devices. Unlike conventional techniques using shadow-masking, small geometry structures arranged in measurement arrays can be obtained. The effect of substrate temperature on the electrical and morphological characteristics of germanium films is studied and an optimum temperature of 400°C is selected. The structure consists of two perpendicular 1000 Å thick germanium resistors on a 25 μm thick mica substrate. A bi-layer Al-Cu metallization is used to allow soldering. A modified process is then suggested which facilitates precise control of film conductivity and results in better matching from batch to batch. The fabricated sensors have a gauge factor of about 10 and good long-term stability.
Keywords :
arrays; assembling; batch processing (industrial); crystal morphology; electric sensing devices; electrical conductivity; elemental semiconductors; germanium; photolithography; resistors; semiconductor device metallisation; semiconductor thin films; soldering; strain gauges; 1000 angstrom; 25 micron; 400 C; Al2O3-K2O-SiO2; Cu-Al-Ge-Al2O3K2OSiO2; batch fabrication; batch to batch matching; bi-layer Al-Cu metallization; electrical characteristics; film conductivity control; germanium films; lithography patterning; long-term stability; measurement arrays; mica substrate; miniaturized thin-film germanium strain gauge; morphological characteristics; optimum substrate temperature; perpendicular germanium resistors; sensor gauge factor; shadow-masking; small geometry structures; soldering; substrate temperature; Capacitive sensors; Fabrication; Geometry; Germanium; Lithography; Metallization; Resistors; Substrates; Temperature; Transistors;
Conference_Titel :
Microelectronics, 1999. ICM '99. The Eleventh International Conference on
Print_ISBN :
0-7803-6643-3
DOI :
10.1109/ICM.2000.884808
