A semiconductor integrated circuit is so structured that a first insulating layer is formed on a surface of a semiconductor chip and a second insulating layer covers an entire region of the surface of the semiconductor chip. The subject invention can involve passing a halide gas over an area of Cu such that CuX, or CuX and CuX2, are formed, where X is the halide. Light sensor detects light from the base side that has passed through glass substrate on the surface of glass substrate. A squeegee presses the paper to the wall as it is being unwound. Under reverse bias, the barrier is substantially reduced or disappears, allowing charge carriers to move from the absorbing P region into the N region where they are detected.