Dl. Partin et al., The influence of stoichiometry on the growth of tellurium-doped indium antimonide for magnetic field sensors, J CRYST GR, 195(1-4), 1998, pp. 378-384
Indium antimonide magnetoresistors are used as magnetic position sensors in
very demanding automotive environments such as crankshaft and camshaft sen
sors for engine control. The use of tellurium as an n-type dopant was studi
ed using Hall effect measurements up to 200 degrees C, Hall depth profiling
, and secondary ion mass spectroscopy. The films were grown by metal organi
c chemical vapor deposition using trimethyl indium, trisdimethylamino antim
ony, and diethyl telluride. It was found that the incorporation of telluriu
m strongly depends upon the V/III ratio during growth, implying that it is
influenced by the availability of antimony vacancies. Thus, our results sho
w that the reproducibility of tellurium doping is not limited by memory eff
ects in a well-designed reactor, but by the control of stoichiometry. It is
now possible to grow films with optimum doping profile and with good unifo
rmity and reproducibility over hundreds of growth runs. These films can be
used to make magnetoresistors that have good sensitivity to a magnetic fiel
d and good stability over a wide temperature range. (C) 1998 Elsevier Scien
ce B.V. All rights reserved.