Monolithically integrated multi-sensor device on a semiconductor substrate and method therefor

Abstract

A monolithically integrated multi-sensor (MIMS) is disclosed. A MIMs integrated circuit comprises a plurality of sensors. For example, the integrated circuit can comprise three or more sensors where each sensor measures a different parameter. The three or more sensors can share one or more layers to form each sensor structure. In one embodiment, the three or more sensors can comprise MEMs sensor structures. Examples of the sensors that can be formed on a MIMs integrated circuit are an inertial sensor, a pressure sensor, a tactile sensor, a humidity sensor, a temperature sensor, a microphone, a force sensor, a load sensor, a magnetic sensor, a flow sensor, a light sensor, an electric field sensor, an electrical impedance sensor, a galvanic skin response sensor, a chemical sensor, a gas sensor, a liquid sensor, a solids sensor, and a biological sensor.

What is claimed is: 
     
         1 . A monolithically integrated multi-sensor (MIMS) comprising:
 a first sensor configured to measure a first parameter;   a second sensor configured to measure a second parameter;   a third sensor configured to measure a third parameter wherein the first, second, and third parameters are different, wherein the first, second, and third sensors are formed on or in a single semiconductor substrate using a monolithic semiconductor process, and wherein the a layer of the monolithic semiconductor process is common to the first, second, and third sensors.   
     
     
         2 . The monolithically integrated multi-sensor of  claim 1  wherein the first sensor is a micro-electrical-mechanical system (MEMS) sensor. 
     
     
         3 . The monolithically integrated multi-sensor of  claim 2  wherein the second sensor is a MEMS sensor. 
     
     
         4 . The monolithically integrated multi-sensor of  claim 3  wherein the third sensor comprises a MEMS sensor. 
     
     
         5 . The monolithically integrated multi-sensor of  claim 1  wherein the layer of the monolithic semiconductor process is patterned and etched simultaneously on the first, second, and third sensors. 
     
     
         6 . The monolithically integrated multi-sensor of  claim 1  wherein the monolithically integrated multi-sensor comprises three or more sensors. 
     
     
         7 . The monolithically integrated multi-sensor of  claim 1  wherein the first, second, and third sensors respectively comprise an inertial sensor, a pressure sensor, and an acoustic sensor. 
     
     
         8 . The monolithically integrated multi-sensor of  claim 7  wherein the layer is a polycrystalline silicon layer that forms a protective cap of the inertial sensor, a pressure sensitive diaphragm of the pressure sensor, and a sound sensitive membrane of the acoustic sensor. 
     
     
         9 . The monolithically integrated multi-sensor of  claim 7  wherein the layer is a silicon on insulator layer that forms a dynamic element of the inertial sensor, a static element of the pressure sensor, and a static element of the acoustic sensor. 
     
     
         10 . The monolithically integrated multi-sensor of  claim 9  wherein the dynamic element is a proof mass or a suspension spring of the inertial sensor, wherein the static element is an electrode of the pressure sensor, and wherein the static element is an electrode of the acoustic sensor. 
     
     
         11 . The monolithically integrated multi-sensor of  claim 1  wherein a second layer of the monolithic semiconductor process is common to the first, second, and third sensors. 
     
     
         12 . The monolithically integrated multi-sensor of  claim 1  wherein the layer is an electrically conductive layer. 
     
     
         13 . The monolithically integrated multi-sensor of  claim 1  wherein the layer is an electrically insulating layer. 
     
     
         14 . The monolithically integrated multi-sensor of  claim 1  wherein the layer is a sacrificial layer. 
     
     
         15 . The monolithically integrated multi-sensor of  claim 1  wherein the layer is a silicon layer comprising a polycrystalline layer or a single crystalline layer. 
     
     
         16 . The monolithically integrated multi-sensor of  claim 1  further including a humidity sensor. 
     
     
         17 . The monolithically integrated multi-sensor of  claim 1  further including a temperature sensor. 
     
     
         18 . The monolithically integrated multi-sensor of  claim 1  wherein the layer is deposited overlying the single semiconductor substrate by chemical vapor deposition. 
     
     
         19 . The monolithically integrated multi-sensor of  claim 1  wherein the monolithic semiconductor process to form the first, second, and third sensors comprises one or more layers formed overlying the single semiconductor substrate, wherein the one or more layers are patterned, and wherein the one or more layers are etched. 
     
     
         20 . The monolithically integrated multi-sensor of  claim 1  wherein at least one of the first, second, or third sensors is sealed from an external environment and wherein at least one of the first, second, or third sensors is exposed to the external environment.