Temperature independent semiconductor resistor and method of making same
AssigneeGeneral Motors Corporation
InventorMichael W. Collver
Life of this patent
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Abstract
A polycrystalline film having an electrical resistivity independent of temperature is disclosed. The film has substantially only one crystalline phase. The crystals forming that phase are of a semiconductive material supersaturated with a deep level dopant and have average dimensions from about 200 to 10,000 angstroms. At least about 10 atomic percent of the deep level dopant is dispersed within the semiconductive material crystals forming the one crystalline phase. The film is useful in making an electrical resistor whose resistance value is independent of temperature from about 4.degree. Kelvin to approximately 373.degree. Kelvin. Aging effects limit utility at significantly higher temperatures.
Claims6
A semiconductive film comprising, a layer of polycrystalline semiconductive material having substantially only one crystalline phase, with crystals forming that phase being supersaturated with a deep level dopant and having a grain size greater than 200 angstroms.
A semiconductive film that has an electrical resistivity of substantially constant characteristics throughout a temperature range of about 4.degree. - 373.degree. Kelvin, said film comprising a layer of polycrystalline semiconductive material having substantially only one crystalline phase, with crystals forming that phase having a grain size of about 500 - 10,000 angstroms and being supersaturated with a dopant having an activation energy, when at room temperature and at concentrations below its normal limit of solid solubility in said semiconductive material, greater than about 0.1 electron volt.
An electrical resistor that is substantially constant in its resistance throughout a temperature range of about 4.degree. - 373.degree. Kelvin, said resistor comprising:
- a substrate having a surface;
- a layer of polycrystalline semiconductive material selected from the group consisting of silicon and germanium on said surface, said layer having substantially only one crystalline phase and the crystals forming that phase having a grain size of about 500 - 10,000 angstroms;
- `atoms of a deep level dopant dispersed in supersaturated solid solution within said crystals in a concentration within about 10 - 18 atomic percent and being within about 1 atomic percent of a metal-semiconductor transition concentration with respect to electrical characteristics;
- said deep level dopant having an activation energy greater than about 0.1 electron volt, when at room temperature and at concentrations below its normal limit of solid solubility in said semiconductive material;
- and
- means for passing electrical current though said layer.
An electrical resistors that is substantially constant in resistance throughout a temperature range of about 4.degree. - 373.degree. Kelvin, said resistor comprising:
- a substrate having a surface;
- a layer of polycrystalline semiconductive material selected from the group consisting of silicon and germanium on said surface, said layer having substantially only one crystalline phase and the crystals forming that phase being greater than 200 angstroms and having an average dimension of the order of 1,000 angstroms;
- atoms of a deep level dopant selected from the group consisting of nickel and cobalt dispersed in supersaturated solution within said crystals in a concentration of about 12 - 14 atomic percent;
- and
- means for passing electrical current through said layer.
A method of making a semiconductor resistive film having electrical resistance characteristics constant over a temperature range of about 4.degree. - 373.degree. Kelvin, said resistive film comprising, heating a substrate to a temperature of about 400.degree. - 700.degree. C. in an evacuated chamber, and simultaneously vacuum depositing onto said heated substrate a semiconductive material and deep level dopant at relative rates that will produce a single phase polycrystalline layer having crystals of semiconductive material greater than 200 angstroms and supersaturated with said deep level dopant.
A method of making a resistor having electrical resistance characteristics constant over a temperature range of about 4.degree. - 373+ Kelvin, said resistor comprising, heating a substrate to a temperature of about 400.degree. - 700.degree. C. in an evacuated chamber, and simultaneously vacuum codepositing onto said heated substrate a semiconductive material selected from the group consisting of germanium and silicon and a deep level dopant selected from the group consisting of nickel and cobalt, said semiconductive material and deep level dopant being deposited in an atomic ratio of about 9:1, respectively, and producing a polycrystalline layer having only one crystalline phase, with crystals forming that phase having a deep level dopant dispersed throughout in a concentration of about 10 - 14 atomic percent and said crystals having a grain size of about 500 - 10,000 angstroms.
Dependencies are inferred from the claim text.