US 12,392,744 B2
Sensor for measuring a gas property
Julia Isabel Perez Barraza, Unterhaching (DE); Matthias Eberl, Taufkirchen (DE); and Francesco Solazzi, Villach (AT)
Assigned to Infineon Technologies AG, Neubiberg (DE)
Filed by Infineon Technologies AG, Neubiberg (DE)
Filed on Dec. 6, 2021, as Appl. No. 17/457,752.
Claims priority of application No. 102020134366.3 (DE), filed on Dec. 21, 2020.
Prior Publication US 2022/0196585 A1, Jun. 23, 2022
Int. Cl. G01N 27/12 (2006.01); G01N 33/00 (2006.01)
CPC G01N 27/122 (2013.01) [G01N 27/129 (2013.01); G01N 33/005 (2013.01); H01L 2924/0002 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A sensor for measuring a gas property, the sensor comprising:
a semiconductor die that defines a reference cavity and a measuring cavity,
wherein the reference cavity is sealed from an ambient gas,
wherein the measuring cavity is fluidly connected to the ambient gas, and
wherein the semiconductor die includes:
a plurality of reference sensor elements arranged in the reference cavity; and
a plurality of measuring sensor elements arranged in the measuring cavity,
wherein the plurality of reference sensor elements and the plurality of measuring sensor elements are conductive regions formed within the semiconductor die,
wherein the plurality of reference sensor elements include a first reference sensor element and one or more second reference sensor elements, and
wherein the plurality of measuring sensor elements include a first measuring sensor element and one or more second measuring sensor elements;
a first catalytic layer arranged on the first reference sensor element and configured to react with gas molecules of a gas to induce a modification of one or more electrical properties of the first reference sensor element; and
a second catalytic layer arranged on the first measuring sensor element and configured to react with the gas molecules of the gas to induce a modification of one or more electrical properties of the first measuring sensor element,
wherein the first reference sensor element and the first measuring sensor element are configured to measure a gas concentration of the gas based on catalytic combustion of the first catalytic layer and the second catalytic layer, respectively,
wherein the one or more second reference sensor elements and the one or more second measuring sensor elements are configured to measure the gas concentration of the gas based on a thermal conductivity of the one or more second reference sensor elements and the one or more second measuring sensor elements being modified by an interaction with the gas molecules of the gas,
wherein the first reference sensor element and the first measuring sensor element are electrically connected to form a half bridge circuit, the half bridge circuit configured to provide a first readout signal representative of the gas concentration of the gas, and
wherein the one or more second reference sensor elements and the one or more second measuring sensor elements are electrically connected to form a bridge circuit, the bridge circuit configured to provide a second readout signal representative of the gas concentration of the gas.