U.S. Philips Corporation

Volker Graeger

Rolf U Kobs

Heinrich Zeile

Horst Schafer

August Petersen

Michael Muth

An angle sensor includes at least two angularly spaced sensor units which measure in a contactless manner and whose sensor voltages are similar but angularly shifted sinusoidal functions (sensor characteristic) of the angle .alpha. to be measured relative to a rotatable element and a processing circuit forms an angle sensor voltage which is a measure of the angle .alpha.. Using limited analog circuitry, a wide angular range is obtained and also a monotonously increasing angle sensor voltage which is dependent as linearly as possible on the angle to be measured, in that the sensor voltages are direct voltages which are constant in time. The processing circuit includes limiter circuits (15) whose input receives the sensor voltages (UMA, UMB), and whose output voltages exhibit values (10, 11) which remain constant when a limit value of the sensor voltages is exceeded, and that the output voltages of the limiter circuits (15) are applied to the input of a summing circuit (16) in order to form the angle sensor voltage.

Angle sensor including angularly spaced sensor units

The invention relates to a method of manufacturing a polycrystalline semiconductor resistance layer of silicon on a silicon body. First an insulating layer is formed on the silicon body and then a polycrystalline silicon layer is deposited. To the deposited polycrystalline silicon layer is applied a further polycrystalline silicon layer having a crystallite structure coarser with respect to that of the first polycrystalline silicon layer. The two polycrystalline silicon layers are additionally doped.

Method of manufacturing a polycrystalline semiconductor resistance layer

A pressure sensor comprising a silicon body (1) which is arranged on a substrate (2). The silicon body (1) comprises a cavity (4) in the form of a blind hole, or enclosed chamber which thus forms a diaphragm (5). On the outer surface thereof there is arranged a Wheatstone bridge consisting of piezoresistive resistance elements (6, 7, 8, 9). The voltage/pressure characteristic of this pressure sensor exhibits a non-linearity of more than 1% in the case of pressure loads in excess of 250 bar. This non-linearity must be reduced. Therefore, a further cavity (10) is provided in the silicon body (1) on both sides of the resistance elements (8, 9) arranged at the edge of the diaphragm (5).

Pressure sensor comprising a silicon body

The invention relates to a method of manufacturing a polycrystalline semiconductor resistance layer of silicon on a silicon body. First an insulating layer is formed on the silicon body and then a polycrystalline silicon layer is deposited. To the deposited polycrystalline silicon layer is applied a further polycrystalline silicon layer having a crystallite structure coarser with respect to that of the first polycrystalline silicon layer. The two polycrystalline silicon layers are additionally doped. The invention further relates to a silicon pressure sensor having such a resistance layer.

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Buchholz, Germany

Volker Graeger