Dual thin film precision resistance trimming
AssigneesSTMicroelectronics S.r.l., STMicroelectronics (Grenoble) SAS
InventorsOlivier Le Neel, Pascale Dumont-Girard, Chengyu Niu, Fuchao Wang, Michel Arnoux
Life of this patent
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Abstract
A trimmable resistor for use in an integrated circuit is trimmed using a heater. The heater is selectively coupled to a voltage source. The application of voltage to the heater causes the heater temperature to increase and produce heat. The heat permeates through a thermal separator to the trimmable resistor. The resistance of the trimmable resistor is permanently increased or decreased when the temperature of the resistor is increased to a value within a particular range of temperatures.
Claims19
A trimmable resistance structure, comprising:
- an integrated semiconductor circuit having components in a silicon substrate;
- a resistive structure composed of a material whose resistance is permanently changeable by application of heat thereto, the resistive structure being part of the integrated circuit;
- a dielectric disposed adjacent to the resistive structure;
- a heater disposed adjacent to the dielectric, the dielectric being disposed so as to separate the heater from the resistive structure;
- and
- a switch coupled between the heater and a voltage supply.
A resistor trimming method, comprising:
- applying a voltage to a heater through a switch;
- heating a resistive structure adjacent to the heater;
- permanently changing the resistance value of the resistive structure during the heating step;
- and
- removing the voltage from the heater.
A circuit, comprising:
- an amplifier;
- a trimmable thin film resistor electrically coupled to the amplifier;
- a thin film heater thermally coupled to the trimmable thin film resistor;
- a transistor electrically coupled to the thin film heater to selectively permit current to increase a temperature of the thin film heater;
- and
- a thin film thermal separator disposed between the trimmable thin film resistor and the thin film heater.
Dependencies are inferred from the claim text.