Sanyo Electric Co., Ltd.

Akira Hatsugai

Tsuyoshi Takahashi

Katsuya Okabe

Hirotsugu Hata

Yasunari Tagami

Masayuki Kawaguchi

Disclosed is an optical semiconductor integrated circuit device has an opening portion in an insulating layer, which is formed in a light receiving region of a photodiode stepwise. Thus, a step of the opening portion is reduced, leading to an improvement of a step coverage of a light shadowing film formed on the insulating film so as to cover the insulating film. By the improvement of the step coverage of the opening portion, the light shadowing film located on a plane of the light shadowing film of the photodiode is not broken. A problem that a conventional light shadowing film is broken is solved in the photodiode for a blue laser beam.

Optical semiconductor integrated circuit device

In an existing optical semiconductor integrated circuit device, a multi-layered wiring layer is formed on a top surface of a substrate. Therefore, a film thickness of an insulating layer on a top surface of a photodiode could be uniformed with difficulty. Thus there was a problem in the constitution of the insulating layer wherein light incidence was caused to fluctuate, and thereby a desired sensitivity to light could not be obtained. In an optical semiconductor integrated circuit device according to the present invention, after a multi-layered wiring layer is formed on a top surface of a substrate, an insulating layer on a top surface of an anti-reflection film of a photodiode is dry-etched to remove. At this time, a barrier metal layer is used as an etching stopper film. Thereby, in the invention, a manufacturing process can be simplified and owing to adoption of the dry etching miniaturization can be realized. Furthermore, since the anti-reflection film is exposed from the insulating layer, fluctuation of incident light can be suppressed and the sensitivity to light can be improved.

Manufacturing method of optical semiconductor integrated circuit device

In an existing optical semiconductor integrated circuit device, a silicon nitride film that is an anti-reflection film is used as an etching stopper film at the etching of an insulating film and by means of wet etching the insulating film is removed once for all. Accordingly, there is a problem in that the processing accuracy is poor. In an optical semiconductor integrated circuit device according to the present invention, after a multi-layered wiring layer is formed on a top surface of a silicon substrate, an insulating layer on a top surface of an anti-reflection film of a photodiode is removed by means of dry etching. At this time, a polycrystal silicon film is used as an etching stopper film. Thereby, in the photodiode according to the invention, although the dry etching is used, since a silicon nitride film that is an anti-reflection film is not over-etched, the dispersion of film thickness thereof can be inhibited from occurring. As a result, a photodiode according to the present invention can realize an improvement in the sensitivity of incident light and a miniaturization structure can be realized.

Method of manufacturing optical semiconductor integrated circuit device

A lead electrode is formed to expose an active base region. A lead electrode for an emitter electrode is formed on the lead electrode in an emitter region, through an insulating film. The insulating film on the lead electrode is then etched to form a contact hole. After that, the emitter contact hole is formed to expose the lead electrode. Also, a silicon nitride film SN is interposed between the lead electrode and insulating film and between the lead electrode and LOCOS oxide film each to decrease resistance of the lead electrodes.

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Gunma, Japan

Akira Hatsugai