发明名称 |
Humidity sensor |
摘要 |
A method of making a humidity sensor comprises providing a host device constituted by a semi-conductor substrate (10) and a gate insulator (13) of an insulated gate field effect transistor, forming a layer (14) of poly (vinyl) alcohol (PVA) on the exposed surface of the insulator, heat treating the layer to crystallize and stabilize the PVA, and forming a gate electrode (15) on the PVA layer, so that the gate electrode is porous allowing ambient water vapor to be absorbed by the PVA which, in response, undergoes a change of bulk dielectric constant, thereby causing a change in gate capacitance of the transistor resulting in a detectable change of electrical conductivity in the drain source channel.
|
申请公布号 |
US5004700(A) |
申请公布日期 |
1991.04.02 |
申请号 |
US19900561377 |
申请日期 |
1990.08.01 |
申请人 |
EMI LIMITED;SHARP KABUSHIKI KAISHA |
发明人 |
WEBB, BRIAN C.;PEDLEY, DEREK G.;PROSSER, STEPHEN J.;HIJIKIGAWA, MASAYA;FURUBAYASHI, HISATOSHI |
分类号 |
G01N27/00;G01N27/12;G01N27/414;H01L29/49 |
主分类号 |
G01N27/00 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|