Method of manufacturing semiconductor device

Abstract

A method of manufacturing a semiconductor device includes: forming a first semiconductor layer on a semiconductor substrate; forming a second semiconductor layer above the first semiconductor layer, the second semiconductor layer having a smaller selection ratio of wet-etching than the first semiconductor layer; forming a hole having the semiconductor substrate as a bottom face in a supporting member holding area by removing by etching the second semiconductor layer and the first semiconductor layer in the supporting member holding area; forming a supporting member film above the semiconductor substrate to fill in the hole and to cover the second semiconductor layer; forming a mask pattern above the supporting member film, the mask pattern covering a supporting member area and exposing another area; dry-etching the second semiconductor layer and the first semiconductor layer in sequence using the mask pattern as a mask to form a supporting member abutting on the semiconductor substrate at the bottom face of the hole, and to form an aperture face under the supporting member, the aperture face exposing a side face of the first semiconductor layer; forming a hollow section between the second semiconductor layer and the semiconductor substrate by wet-etching the first semiconductor layer via the aperture face; and forming an insulating film inside the hollow section. In this case, the supporting member area includes a first supporting member area, a second supporting member area intersecting the first supporting member area, and a protruding area protruding from an intersection between the first supporting member area and the second supporting member area, and the supporting member holding area is disposed at a position overlapping the protruding area in plan view and distant from the intersection area.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanying drawings, wherein like numbers refer to like elements.

FIGS. 1A and 1B are explanatory views of a supporting member area 110 and supporting member holding areas 130 according to a first embodiment.

FIGS. 2A and 2B are explanatory views of a supporting member area 200 and a supporting member holding area 230 according to a second embodiment.

FIG. 3 is a view showing an example of an SRAM according to the second embodiment.

FIG. 4 is a view showing another example of an SRAM according to the second embodiment.

FIG. 5 is an explanatory view of a supporting member area 310 and a supporting member holding area 330 according to a third embodiment.

FIG. 6 is an explanatory view of a supporting member area 410 and supporting member holding areas 430 according to a fourth embodiment.

FIG. 7 is an explanatory view of a supporting member area 510 and supporting member holding areas 530 according to a fifth embodiment.

FIG. 8 is an explanatory view of a supporting member area 610 and supporting member holding areas 630 according to a sixth embodiment.

FIGS. 9A through 9D are diagrams (anterior half showing a method of manufacturing a semiconductor device according to an embodiment

FIGS. 10A through 10D are diagrams (posterior halt showing the method of manufacturing a semiconductor device according to the embodiment

FIG. 11 is a view showing a related art example and a problem thereof.

Claims

1. A method of manufacturing a semiconductor device, comprising: forming a first semiconductor layer on a semiconductor substrate;forming a second semiconductor layer above the first semiconductor layer, the second semiconductor layer having a smaller selection ratio of wet-etching than the first semiconductor layer;forming a hole having the semiconductor substrate as a bottom face in a supporting member holding area by removing by etching the second semiconductor layer and the first semiconductor layer in the supporting member holding area;forming a supporting member film above the semiconductor substrate to fill in the hole and to cover the second semiconductor layer;forming a mask pattern above the supporting member film, the mask pattern covering a supporting member area and exposing another area;dry-etching the second semiconductor layer and the first semiconductor layer in sequence using the mask pattern as a mask to form a supporting member abutting on the semiconductor substrate at the bottom face of the hole, and to form an aperture face under the supporting member, the aperture face exposing a side face of the first semiconductor layer;forming a hollow section between the second semiconductor layer and the semiconductor substrate by wet-etching the first semiconductor layer via the aperture face; andforming an insulating film inside the hollow section,wherein the supporting member area includes: a first supporting member area;a second supporting member area intersecting the first supporting member area;a first protruding area protruding from an intersection between the first supporting member area and the second supporting member area in a longitudinal direction of the first supporting member area; anda second protruding area protruding from the intersection area in a longitudinal direction of the second supporting member area,the supporting member holding area is disposed at least one of a position overlapping the first protruding area in plan view and distant from the intersection area and a position overlapping the second protruding area in plan view and distant from the intersection area.

2. A method of manufacturing a semiconductor device, comprising: forming a first semiconductor layer on a semiconductor substrate;forming a second semiconductor layer above the first semiconductor layer, the second semiconductor layer having a smaller selection ratio of wet-etching than the first semiconductor layer;forming a hole having the semiconductor substrate as a bottom face in a supporting member holding area by removing by etching the second semiconductor layer and the first semiconductor layer in the supporting member holding area;forming a supporting member film above the semiconductor substrate to fill in the hole and to cover the second semiconductor layer;forming a mask pattern above the supporting member film, the mask pattern covering a supporting member area and exposing another area;dry-etching the second semiconductor layer and the first semiconductor layer in sequence using the mask pattern as a mask to form a supporting member abutting on the semiconductor substrate at the bottom face of the hole, and to form an aperture face under the supporting member, the aperture face exposing a side face of the first semiconductor layer;forming a hollow section between the second semiconductor layer and the semiconductor substrate by wet-etching the first semiconductor layer via the aperture face; andforming an insulating film inside the hollow section,wherein the supporting member area includes: a first supporting member area;a second supporting member area intersecting the first supporting member area; anda protruding area protruding from an intersection between the first supporting member area and the second supporting member area,the supporting member holding area is disposed at a position overlapping the protruding area in plan view and distant from the intersection area.

3. A method of manufacturing a semiconductor device, comprising: forming a first semiconductor layer on a semiconductor substrate;forming a second semiconductor layer above the first semiconductor layer, the second semiconductor layer having a smaller selection ratio of wet-etching than the first semiconductor layer;forming a hole having the semiconductor substrate as a bottom face in a supporting member holding area by removing by etching the second semiconductor layer and the first semiconductor layer in the supporting member holding area;forming a supporting member film above the semiconductor substrate to fill in the hole and to cover the second semiconductor layer;forming a mask pattern above the supporting member film, the mask pattern covering a supporting member area and exposing another area;dry-etching the second semiconductor layer and the first semiconductor layer in sequence using the mask pattern as a mask to form a supporting member abutting on the semiconductor substrate at the bottom face of the hole, and to form an aperture face under the supporting member, the aperture face exposing a side face of the first semiconductor layer;forming a hollow section between the second semiconductor layer and the semiconductor substrate by wet-etching the first semiconductor layer via the aperture face; andforming an insulating film inside the hollow section,wherein the supporting member area includes: a first supporting member area;a second supporting member area intersecting the first supporting member area; anda protruding area protruding from at least one of the first supporting member area and the second supporting member area except the intersection area between the first supporting member area and the second supporting member area,the supporting member holding area is disposed at a position overlapping the protruding area in plan view and distant from all of the intersection area, the first supporting member area, and the second supporting member area.