Method for manufacturing a semiconductor device

Abstract

A step for etching a wiring-structure layer and the like on a light-receiving part of a light detector and forming an apertured part is simplified. A silicon nitride film 86 is formed on a semiconductor substrate 60 by CVD or the like, and a layered structure 88 that has the wiring-structure layer is then formed. A photoresist film 122 having an aperture above the light-receiving part is formed on the layered structure 88, and the layered structure 88 is etched using the photoresist layer as an etching mask. The type of etching and the conditions under which the etching is performed are such that the etching selectivity of the interlayer insulating film with respect to a silicon nitride film will be maintained. In the etching process, the silicon nitride film 86 functions as an etching stopper. The silicon nitride film 86 that has been exposed at a bottom part of the apertured part 116 constitutes an antireflective film.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view showing structures of a light-receiving part and circuit part of a conventional light detector;

FIGS. 2A through 2D are schematic views showing cross-sectional structures of the conventional light detector during major steps of forming an apertured part;

FIG. 3 is a schematic plan view of a semiconductor device that is a light detector according to an embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view showing structures of a light-receiving part and a circuit part of the light detector that is an embodiment of the present invention; and

FIGS. 5A through 5D are schematic views showing cross-sectional structures of the light detector of an embodiment of the present invention during major steps for forming an apertured part.

Claims

1. A method for manufacturing a semiconductor device having a light-receiving part formed on a semiconductor substrate and an apertured part provided to a structure layer on the substrate corresponding to a position of the light-receiving part; the method for manufacturing a semiconductor device comprising the steps of: layering a base film in which a base film that is resistant to corrosion in the etching process used to form the apertured part is layered on the semiconductor substrate;layering a structure layer in which the structure layer on the substrate is layered on a surface of the base film; andforming an apertured part in which the structure layer on the substrate is etched using the base film as an etching stopper, and the apertured part is formed.

2. The method for manufacturing a semiconductor device of claim 1, wherein the structure layer on the substrate is a wiring-structure layer in which a wiring and an interlayer insulating film are layered.

3. The method for manufacturing a semiconductor device of claim 1, wherein the base film is a silicon nitride film.

4. The method for manufacturing a semiconductor device of claim 1, wherein the thickness of the base film layered in the step of layering the base film is set on the basis of the sum of the thickness of the base film etched in the step of forming the apertured part and the thickness of an antireflective film for light incident on the light-receiving part.