Voltage variable capacitor
First Claim
Patent Images
1. A voltage variable capacitor, comprising:
- a semiconductor having a layer of semiconductive material of a higher resistivity than the semiconductor;
a depletion layer formed in the high resistivity layer;
an insulating layer formed on the high resistivity layer, said insulating layer being a metal oxide having a dielectric constant greater than the dielectric constant of the semiconductor; and
an conductive electrode formed on the dielectric layer.
2 Assignments
0 Petitions
Accused Products
Abstract
A voltage variable capacitor (10) has as the base substrate a silicon wafer with a layer of high resistivity semiconductor material on top of the substrate. An insulating layer (16) of a metal oxide having a dielectric constant greater than the dielectric constant of the semiconductors (12), such as zirconium titanate, is formed on top of the high resistivity layer, and a metal electrode (18) is formed on the insulating layer (16). When the electrode is energized, a depletion layer (20) is formed in the high resistivity layer. By varying the voltage applied to the electrode, the capacitance of the device is altered.
-
Citations
16 Claims
-
1. A voltage variable capacitor, comprising:
-
a semiconductor having a layer of semiconductive material of a higher resistivity than the semiconductor; a depletion layer formed in the high resistivity layer; an insulating layer formed on the high resistivity layer, said insulating layer being a metal oxide having a dielectric constant greater than the dielectric constant of the semiconductor; and an conductive electrode formed on the dielectric layer. - View Dependent Claims (4, 5, 6, 7)
-
-
2. A voltage variable capacitor, comprising:
-
a semiconductor having a layer of semiconductive material of a higher resistivity than the semiconductor; a depletion layer formed in the high resistivity layer; an insulating layer formed on the high resistivity layer, wherein said insulating layer is a metal oxide compound wherein the metal comprises at least first and second components selected from the group consisting of barium, lead, lithium, molybdenum, neodymium, niobium, strontium, tantalum, titanium, tungsten, vanadium, and zirconium, the insulating layer having a dielectric constant greater than the dielectric constant of the semiconductor; and a conductive electrode formed on the insulating layer.
-
-
3. A voltage variable capacitor, comprising:
-
a semiconductor having a layer of semiconductive material of a higher resistivity than the semiconductor; a depletion layer formed in the high resistivity layer; an insulating layer formed on the high resistivity layer, wherein said insulating layer is an oxide selected from the group consisting of oxides of barium, lead, lithium, molybdenum, neodymium, niobium, strontium, tantalum, titanium, tungsten, vanadium, and zirconium, the insulating layer having a dielectric constant greater than the dielectric constant of the semiconductor; and a conductive electrode formed on the insulating layer.
-
-
8. An integrated circuit having a voltage variable capacitor, said circuit comprising:
-
a semiconductor having a layer of semiconductive material of a higher resistivity than the semiconductor; a depletion layer formed in the high resistivity layer; an insulating layer formed on the high resistivity layer, said insulating layer being a metal oxide having a dielectric constant greater than the dielectric constant of the semiconductor; and a conductive electrode formed on the insulating layer.
-
-
9. A voltage variable thin film capacitor, comprising;
-
a semiconductor having a layer of a high resistivity semiconductive material thereon; an insulating layer formed on the high resistivity layer, comprising; a thin film of zirconium titanate; a metal electrode formed on the zirconium titanate; and a depletion layer formed in the high resistivity layer upon electrically energizing the capacitor.
-
- 10. An insulating layer for a voltage variable capacitor, comprising a low-loss non-ferroelectric material having a dielectric constant equal to or greater than 40.
-
11. An insulating layer for a voltage variable capacitor, comprising a low-loss non-ferroelectric material having a dielectric constant equal to or greater than 40, wherein the insulating layer is a metal oxide wherein the metal comprises at least first and second components selected from the group consisting of barium, lead, lithium, molybdenum, neodymium, niobium, strontium, tantalum, titanium, tungsten, vanadium, and zirconium.
-
12. An insulating layer for a voltage variable capacitor, comprising a low-loss non-ferroelectric material having a dielectric constant equal to or greater than 40, wherein the insulating layer is an oxide selected from the group consisting of oxides of barium, lead, lithium, molybdenum, neodymium, niobium, strontium, tantalum, titanium, tungsten, vanadium, and zirconium.
-
14. A method of making a voltage variable capacitor, comprising the steps of:
-
depositing a high resistivity layer of semiconductive material on a semiconductor having the same conductivity type; depositing a layer of a metal oxide, metal titanate or metal niobate insulating material having a dielectric constant greater than that of the semiconductor on the surface of the high resistivity layer; forming an electrode on the insulating material; and applying a voltage to the electrode in order to form a depletion layer in the high resistivity layer. - View Dependent Claims (15)
-
-
16. A radio having a resonator, said resonator comprising:
- at least one voltage variable capacitor comprising;
a semiconductor substrate having a layer of a high resistivity semiconductive material thereon; a depletion layer formed in the high resistivity layer; an insulating layer formed on the high resistivity layer, comprising a thin film of zirconium titanate; and an electrode formed on the zirconium titanate in an area directly above the depletion layer.
- at least one voltage variable capacitor comprising;
Specification