Semiconductor pressure sensor and method of manufacturing same

Claim 2

A semiconductor pressure sensor comprising: a first semiconductor substrate including therein semiconductor means for electronically processing a pressure; an isolation layer formed on one surface of said first semiconductor substrate, having a first surface attached to said one surface of said first semiconductor substrate and a second surface opposite said first surface, and having an outer peripheral side surface portion, a second semiconductor substrate formed on said second surface of said isolation layer, and provided with a portion into which a pressurized medium to be measured is introduced, said second semiconductor substrate being provided with an outer peripheral side surface portion, formed at a position apart from said outer peripheral side surface portion of said isolation layer by a predetermined length sufficient to remove electrical influences which effect said semiconductor means formed in said first semiconductor substrate, said electrical influences being from said outer peripheral side surface portion of said second semiconductor substrate, a strain, detecting potion formed at a position in said first semiconductor substrate opposite to said pressurized medium introducing portion in said second semiconductor substrate, for detecting a pressure of a pressurized medium to be measured and introduced into said pressurized medium introducing portion and producing an indication to said semiconductor means indicative thereof.

Claim 3

A semiconductor pressure sensor according to claim 1, wherein said strain detecting portion is constituted by a piezoresistance layer formed in said first semiconductor substrate, and said semiconductor means is formed between said piezoresistance layer and said outer peripheral side surface portion of said first semiconductor substrate.

Claim 4

A semiconductor pressure sensor according to claim 1, wherein a distance between said outer peripheral side surface portion of said isolation layer and said outer peripheral side surface portion of said second semiconductor region is larger than a thickness of said isolation layer.

Claim 5

A semiconductor pressure sensor according to claim 3, wherein said distance is obtained by forming the outer peripheral side surface of said isolation layer in a tapered configuration.

Claim 6

A semiconductor pressure sensor according to claim 1, wherein said pressurized medium introducing portion is extended directly to a rear part of said strain detecting portion and extends through said second and first semiconductor substrates.

Claim 7

A semiconductor pressure sensor according to claim 1, wherein said first semiconductor substrate is made of a single crystal semiconductor.

Claim 8

A semiconductor pressure sensor according to claim 1, wherein said peripheral side surface of said second semiconductor substrate is located at least 2 μm inside of an outermost part of said peripheral side surface of said isolation layer.

Claim 9

A semiconductor pressure sensor comprising: a first semiconductor substrate having an outer peripheral side surface portion and provided with a portion into which a pressurized medium to be measured is introduced. an isolation layer formed on one surface of said first semiconductor substrate, having a first surface attached to said one surface of said first semiconductor substrate and a second surface opposite said first surface, and having an outer peripheral side surface portion, a second semiconductor substrate formed on said second surface of said isolation layer and provided with a semiconductor structure for electrically processing a pressure detection, said second semiconductor substrate being provided with an outer peripheral side surface portion which is formed at a position apart from said outer peripheral side surface portion of said isolation layer by a predetermined length sufficient to remove electrical influences which affect said semiconductor structure formed in said second semiconductor substrate, which influences are through said outer peripheral side surface portion of said second semiconductor substrate and through said outer peripheral side surface portion of said isolation layer, and a strain detecting portion formed at a position in said second semiconductor substrate opposite to said pressurized medium introduced portion formed in said first semiconductor substrate for detecting a pressure of a pressurized medium to be measured and introduced into said pressurized medium introducing portion and for producing an indication thereof to said semiconductor structure.

Claim 10

A semiconductor pressure sensor comprising: a first semiconductor substrate having an outer peripheral side surface portion and provided with a portion into which a pressurized medium to be measured is introduced. an isolation layer formed on one surface of said first semiconductor substrate, having a first surface attached to said one surface of said first semiconductor substrate and a second surface opposite said first surface, and having an outer peripheral side surface portion, a second semiconductor substrate formed on said second surface of said isolation layer and provided with a semiconductor structure for electrically processing a pressure detection, said second semiconductor substrate being provided with an outer peripheral side surface portion which is formed at a position apart from said outer peripheral side surface portion of said isolation layer by a predetermined length sufficient to remove electrical influences which affect said semiconductor structure formed in said second semiconductor substrate, which influences are through said outer peripheral side surface portion of said second semiconductor substrate and through said outer peripheral side surface portion of said isolation layer, and a strain detecting portion formed at a position in said second semiconductor substrate opposite to said pressurized medium introduced portion formed in said first semiconductor substrate for detecting a pressure of a pressurized medium to be measured and introduced into said pressurized medium introducing portion and for producing an indication thereof to said semiconductor structure.

Claim 11

A semiconductor pressure sensor according to claim 8, wherein said strain detecting portion is constituted by a piezoresistance layer formed in an vicinity of said semiconductor structure formed in said second semiconductor substrate, and said semiconductor structure is formed between said piezoresistance layer and said outer peripheral side surface portion of said second semiconductor substrate.

Claim 12

A semiconductor pressure sensor according to claim 9, wherein said outer peripheral side surface portion of said second semiconductor substrate is exposed to the atmosphere, and further comprising an insulating film, on an upper surface of said second semiconductor substrate opposite to the surface on which said isolation layer is formed.

Claim 13

A semiconductor pressure sensor according to claim 9, further comprising an isolating film covering said outer peripheral side surface portion of said second semiconductor substrate.

Claim 14

A semiconductor pressure sensor according to claim 8, wherein said semiconductor pressure sensor further comprises: a diaphragm structure formed on said second semiconductor substrate and at a position opposite to said pressurized medium introducing portion, and wherein said pressurized medium introducing portion is formed by penetrating said first semiconductor substrate, said isolation layer and said second semiconductor substrate, to extend a tip portion thereof directly to a portion on which said diaphragm structure is located, and an inside surface of said pressurized medium introducing portion formed in said second semiconductor is covered with another isolating film, said strain detecting portion being formed on said portion on which said diaphragm structure is located, said diaphragm structure being provided thereon, and said semiconductor structure being formed between a portion on which said pressurized medium introducing portion is formed in said second semiconductor substrate and said outer peripheral side surface portion of said second semiconductor substrate.

Claim 15

A semiconductor pressure sensor, directly mounted on a device related to an engine of an automobile, for detecting a pressure of a medium to be measured, used in said device, wherein said pressure sensor comprises: a housing provided on said device and including a pressurized medium introducing device therein for introducing a pressurized medium to be measured therein; a first semiconductor substrate having upper and lower surfaces and an outer peripheral side surface portion extending between said upper and lower surfaces, and provided with a pressurized medium introducing portion, wherein said lower surface of said first semiconductor substrate is connected to said pressurized medium introducing device, whereby said pressurized medium introduced by said pressurized medium introducing device is introduced into said pressurized medium introducing portion; a second semiconductor substrate having upper and lower surfaces and an outer peripheral side surface portion extended between said upper and lower surfaces and provided with a semiconductor structure for electronically processing a pressure detection; a strain detecting portion formed in a position in said second semiconductor substrate opposite to said pressurized medium introducing portion formed in said first semiconductor substrate, and detecting a pressure of a pressurized medium to be measured and introduced into said pressurized medium introducing portion; and an isolating layer provided between said upper surface of said first semiconductor substrate and said lower surface of said second semiconductor substrate to serve as an electrical insulator, and having an outer peripheral side surface portion extending between a first surface coupled to said first semiconductor substrate and a second surface coupled to said second semiconductor substrate, wherein each location of the outer peripheral side surface portions of said isolation layer, said first semiconductor substrate and said second semiconductor substrate, is determined respectively so as to remove electrical influences which affect said semiconductor structure formed in said second semiconductor substrate, caused by influences .[.through.]. .Iadd.from .Iaddend.said outer peripheral side surface portion of said .[.second.]. .Iadd.first .Iaddend.semiconductor substrate and through said outer peripheral side surface portion of said isolation layer.

Claim 16

A semiconductor pressure sensor, directly mounted on a device related to an engine of an automobile, for detecting a pressure of a medium to be measured, used in said device, wherein said pressure sensor comprises: a housing provided on said device and including a pressurized medium introducing device therein for introducing a pressurized medium to be measured therein; a first semiconductor substrate having upper and lower surfaces and an outer peripheral side surface portion extending between said upper and lower surfaces, and provided with a pressurized medium introducing portion, wherein said lower surface of said first semiconductor substrate is connected to said pressurized medium introducing device, whereby said pressurized medium introduced by said pressurized medium introducing device is introduced into said pressurized medium introducing portion; a second semiconductor substrate having upper and lower surfaces and an outer peripheral side surface portion extended between said upper and lower surfaces and provided with a semiconductor structure for electronically processing a pressure detection; a strain detecting portion formed in a position in said second semiconductor substrate opposite to said pressurized medium introducing portion formed in said first semiconductor substrate, and detecting a pressure of a pressurized medium to be measured and introduced into said pressurized medium introducing portion; and an isolating layer provided between said upper surface of said first semiconductor substrate and said lower surface of said second semiconductor substrate to serve as an electrical insulator, and having an outer peripheral side surface portion extending between a first surface coupled to said first semiconductor substrate and a second surface coupled to said second semiconductor substrate, wherein each location of the outer peripheral side surface portions of said isolation layer, said first semiconductor substrate and said second semiconductor substrate, is determined respectively so as to remove electrical influences which affect said semiconductor structure formed in said second semiconductor substrate, caused by influences .[.through.]. .Iadd.from .Iaddend.said outer peripheral side surface portion of said .[.second.]. .Iadd.first .Iaddend.semiconductor substrate and through said outer peripheral side surface portion of said isolation layer.

Claim 17

A semiconductor pressure sensor according to claim 13, wherein said device with relation to an engine is a surge tank, and said pressurized medium introducing device is a device for introducing a pressurized medium into said surge tank.

Claim 18

A semiconductor pressure sensor according to claim 14, wherein said pressurized medium introducing device is provided with means for preventing foreign particles introduced from said surge tank from entering said pressurized medium introducing portion formed in said first semiconductor substrate.

Claim 19

A semiconductor pressure sensor according to claim 14, wherein said outer peripheral side surface portion of said .[.second.]. .Iadd.first .Iaddend.semiconductor substrate is formed at a position apart from said outer peripheral side surface portion of said isolation layer by a predetermined length sufficient to remove electrical influences which affect said semiconductor structure formed in said second semiconductor substrate from said outer peripheral side surface portion of said .[.second.]. .Iadd.first .Iaddend.semiconductor substrate through said outer peripheral side surface portion of said isolation layer.

Claim 20

A semiconductor pressure sensor according to one of claims 1 to 8, wherein at least one of the outer peripheral side surfaces of said fist and said second semiconductor substrates is located inside of an outermost peripheral side surface of said isolation layer by said predetermined length.

Claim 21

A semiconductor pressure sensor according to claim 17, wherein said predetermined length is determined in such a way that a distance between said outer peripheral side surface portion of said first and second semiconductor substrates is a length exceeding a thickness of said isolation layer.

Claim 22

A semiconductor pressure sensor according to claim 17, wherein said outer peripheral side surface portion of said isolation layer is formed in a tapered configuration to form said predetermined length.

Claim 23

A semiconductor pressure sensor according to claim 17, wherein said outer peripheral side surface portion of any one of said first and second semiconductor substrates is located at least 2 μm inside said outermost peripheral side surface portion of said isolation layer.

Claim 24

A semiconductor pressure sensor according to claim 17, wherein said isolation layer comprises an impurity region including mobile ions therein and said impurity region thereof is arranged such that it is not in direct contact with the atmosphere introduced into the vicinity of the pressure sensor.

Claim 25

A semiconductor pressure sensor according to claim 12, further comprising a polycrystalline silicon layer provided on a rear surface of said strain detecting portion and in said pressurized medium introducing device.