SCANNING HEAD AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a scanning head whose light emitting side-grating is arranged at the center as much as possible against the light receiving-side grating of the head and a method for manufacturing the head. SOLUTION: A scanning head which is composed of a semiconductor substrate 72.1 and scans a scale plate 78 carrying graduations is provided with many photodetectors 73 patterned and structured on the side face facing the scale plate 78, a light emitting-side grating 74 having one interconnected blind hole and patterned and symmetrically directed to the photodetector 73 patterned and structured on the side face facing the scale plate 78, and one light source 71 on the side face of the grating opposite to the scale plate 78. After the P-N junction of a photodiode is diffused on the surface of the substrate 72.1 on the scale plate 78 side and an oxide layer 75.1 is generated on the same surface of the substrate 72.1, the substrate 72.1 is etched to the portion of the oxide layer 75.1 by etching the substrate 72.1 by an anisotropic etching method from the side face of the substrate 72.1 opposite to the scale plate 78.