A semiconductor substrate is utilized to integrally form a drive circuit and a pixel array to produce a transparent semiconductor device for a light valve comprising a pixel array region and a drive circuit region on a major face of the semiconductor substrate. A stopper film is formed on the major face of the semiconductor substrate at the pixel array region, and a pixel array is formed over the silicon oxide stopper film. A drive circuit is formed on the drive circuit region, and silicon oxide posts are embedded in the major face of the semiconductor substrate at the drive circuit region. A thickness of the semiconductor substrate is then selectively removed from a back face opposite to the major face thereof to reach the stopper film. After the selective removing step, the portion of the semiconductor substrate under the pixel region is completely removed while a portion of the semiconductor substrate under the drive circuit region remains.