초록 ▼

A miniaturized light valve with a surface area on the order of several centimeters may be successfully formed using a composite substrate and an opposing substrate which has thereon an electrode and which is bonded to the composite substrate at a predetermined gap therefrom. An electro-optical mater

A miniaturized light valve with a surface area on the order of several centimeters may be successfully formed using a composite substrate and an opposing substrate which has thereon an electrode and which is bonded to the composite substrate at a predetermined gap therefrom. An electro-optical material, such as a liquid crystal compound, is confined within the gap. The composite substrate includes a single crystal layer of a semiconductor material provided on a lower level insulation layer. The single crystal layer is formed with a source region, a drain region, and a channel region of a MOS transistor, and a gate insulation film is provided on the single crystal layer in alignment with the channel region. Further, a gate electrode is provided on the gate insulation film. The composite substrate further includes a pixel electrode on the upper major surface of an insulation layer deposited over the MOS transistor and in contact with the drain region. The single crystal semiconductor thin film is limited to 0.3 microns in thickness resulting in a light valve characterized in that a parasitic channel and a bipolar action in the MOS transistor are eliminated for the purpose of suppressing an increase in the OFF current, or leakage current caused by incident light radiation onto the transistors.

대표청구항 ▼

[ What is claimed is:] [1.] A light valve for modifying an optical transmission characteristic of an electro-optical substance, comprising: a composite substrate comprising a semiconductor thin film layer provided on a first surface of an underlying insulation layer; a MOS transistor formed on said

[ What is claimed is:] [1.] A light valve for modifying an optical transmission characteristic of an electro-optical substance, comprising: a composite substrate comprising a semiconductor thin film layer provided on a first surface of an underlying insulation layer; a MOS transistor formed on said semiconductor thin film layer and comprising a source region, a drain region, a channel region between the source region and the drain region and being formed of a single crystal semiconductor material having a thickness of not more than 0.3 microns, an internal region located below the channel region, a gate insulation film provided on a surface of said semiconductor thin film layer over the channel region, and a gate electrode provided on said gate insulation film; a pixel electrode provided on said composite substrate in electrical contact with said drain region of said MOS transistor; an opposing substrate bonded to and opposing said composite substrate with a predetermined gap formed therebetween; and an electro-optical material confined within the gap; wherein said MOS transistor is operative to selectively supply an electrical signal to said pixel electrode to change an optical transmission characteristic of the electro-optical material wherein a leakage current of said MOS transistor caused by incident light radiation onto said single crystal semiconductor thin film layer is suppressed.