Patent ID: 6247369
Filing Date: 2001-06-19
Classification: G01L

Abstract:
A cryogenic pressure sensor comprising:a plate having at least one pneumatic port passing therethrough;a substrate, composed of borosilicate, compliantly bonded to said plate, said borosilicate substrate having at least one pneumatic port passing therethrough, each said pneumatic port aligned with one said pneumatic port of said plate;a plurality of silicon pressure die mounted on said borosilicate substrate, each said silicon pressure die located above one said pneumatic port;a Wheatstone bridge circuit formed on said silicon die, said Wheatstone bridge circuit comprising bridge elements of silicon doped with boron to a dopant density level of approximately 1.times.10.sup.19 -10.sup.21 boron/cm.sup.3 ;a bridge element formed on periphery of said silicon die separate from said Wheatstone bridge circuit, said bridge element being insensitive to pressure and providing a temperature measurement of said silicon die, said bridge element comprised of silicon doped with boron to a dopant density level of approximately 1.times.10.sup.19 -10.sup.21 boron/cm.sup.3 ;metallization tracks on said silicon die;a high dopant layer between said tracks and said silicon die, said high dopant layer comprised of silicon doped with boron to a dopant density level of approximately 1.times.10.sup.19 -1.times.10.sup.23 boron/cm.sup.3 ; andmeans for electronically scanning said silicon die to sense pressure.