HOT-CARRIER HALL DEVICES IN CMOS TECHNOLOGY

The sensitivity of Hall devices for a given bias current is often limi ted by short circuiting effects due to the finite length of the struct ure. The reduction of the sensitivity is especially important in small devices where contacts occupy a large part of the active zone. In the present work, we present a novel method to enhance the current-relate d sensitivity. This is done by increasing the current till saturation which leads to the enhancement of the input impedance and thus to the limitation of short circuit. In sufficiently small devices the carrier velocity saturation is the main cause of the resistance increase. Oth er contributions to the sensitivity increase such as junction field ef fect and heating have been taken into account. With the help of comput er simulations, we have separated the different contributions. The vel ocity saturation effect leads up to 40% increase in sensitivity near t he breakdown voltage as compared to the low electric field Hall voltag e. Although the sensitivity increases the overall performance has degr aded when operating in the hot carrier regime. (C) 1998 Elsevier Scien ce S.A. All rights reserved.