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Semiconduction stress sensing apparatus

  • US 4,345,477 A
  • Filed: 12/03/1980
  • Issued: 08/24/1982
  • Est. Priority Date: 12/03/1980
  • Status: Expired due to Term
First Claim
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1. A stress transducing system supported in and on a semiconductor material stress sensing structure having structural portions including substantially a diaphragm and a constraint for constraining said diaphragm at peripheral portions thereof, with said structure having a major surface bounding semiconductor material, said semiconductor material being of a first conductivity type except in selected locations thereof, said major surface being common to both said diaphragm and said constraint, said stress transducing system comprising:

  • a first semiconductor piezoresistive domain in said semiconductor material at a said selected location extending at least in part into said diaphragm, and with said domain being adjacent to said major surface, said first semiconductor piezoresistive domain having first and second terminating regions, said first semiconductor piezoresistive domain having therein a first distribution of dopant atoms with depth into said semiconductor material away from said major surface which leads to said first semiconductor piezoresistive domain being of a second conductivity type and having a temperature coefficient of resistance of a first magnitude which is effective in a first magnitude direction, said first semiconductor piezoresistive domain being a component part of a stress sensing circuit which is capable of providing a stress sensing circuit first output signal at a stress sensing circuit first output region of a magnitude varying in correspondence to changes in magnitude of stress applied to said diaphragm, said stress sensing circuit first output signal varying with such stress, as aforesaid, in a manner characteristic of said first semiconductor piezoresistive domain and remaining portions of said structure to thereby establish a stress sensing characteristic which characteristic also depends upon temperatures occurring in said structure;

    a first semiconductor resistive domain in said semiconductor material at a said selected location and adjacent to said major surface, said first semiconductor resistive domain having first and second terminating regions, said first semiconductor resistive domain having substantially said first distribution of dopant atoms therein leading to said first semiconductor resistive domain being of said second conductivity type and having a temperature coefficient of resistance of substantially said first magnitude which is effective in said first magnitude direction, said first resistive domain being substantially free of effects in electrical behavior in response to stresses applied to said diaphragm, said first semiconductor resistive domain being a component part of a signal processing circuit having a signal processing circuit first input region which is electrically connected to said stress sensing circuit first output region and having a signal processing circuit output region, said signal processing circuit being capable of providing a stress transducer system output signal at said signal processing circuit output region which is a version of said stress sensing circuit first output signal but as compensated to be substantially free of effects of said temperature dependence in said stress sensing circuit characteristic; and

    a first primarily resistive domain adjacent to said major surface and supported by said structure, said first primarily resistive domain having first and second terminating regions, said first primarily resistive domain having a temperature coefficient of resistance of a magnitude substantially less than said first magnitude, said first primarily resistive domain being substantially free of effects in electrical behavior in response to stresses applied to said diaphragm and being a component part of said signal processing circuit.

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