Photo-transistor in MOS thin-film technology and method for production and operation thereof

Claim 1

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicone positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; (c) exposing the photo-transistor to varying light amplitudes to cause variations in drain current; and (d) the photo-transistor being operable with the gate voltage lying anywhere in a range from 100 Hz to 1 Mhz.

Claim 2

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicone positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; (c) exposing the photo-transistor to varying light amplitudes to cause variations in drain current; and (d) the photo-transistor being operable with the gate voltage lying anywhere in a range from 100 Hz to 1 Mhz.

Claim 4

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicon positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; (c) with no light exposure on the photo-transistor, substantially no drain current flows; and (d) with increasing light exposure on the photo-transistor, more and more defects in the boundary region are filled and a surface potential associated with the boundary region follows the alternating gate voltage faster and faster.

Claim 5

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicon positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; (c) with no light exposure on the photo-transistor, substantially no drain current flows; and (d) with increasing light exposure on the photo-transistor, more and more defects in the boundary region are filled and a surface potential associated with the boundary region follows the alternating gate voltage faster and faster.

Claim 8

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicon positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; and (c) with light exposure on the photo-transistor, operating the photo-transistor at frequencies greater than 10 kHz.

Claim 9

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicon positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; and (c) with light exposure on the photo-transistor, operating the photo-transistor at frequencies greater than 10 kHz.

Claim 11

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicon positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; and (c) the alternating voltage applied to the gate being at least 10 kHz and having a potential between 0 to 10 volts.

Claim 12

A method of operating a photo-transistor in MOS thin film technology, comprising steps of: (a) providing the MOS photo-transistor as (1) a semiconductor body comprising polycrystalline silicon having a source zone and drain zone located therein and spaced from one another by an undoped channel region, (2) a gate electrode formed of polycrystalline silicon positioned at and separated from said semiconductor body by an SiO 2 layer generated on the silicon semiconductor body by thermal oxidation, and (3) a high defect density boundary region between the semiconductor body and the SiO 2 layer; (b) applying an alternating voltage to the gate and applying an operating voltage between the source and drain zones; and (c) the alternating voltage applied to the gate being at least 10 kHz and having a potential between 0 to 10 volts.