| abstract |
A depression (22) is formed from a first surface (20) of a semiconductornsubstrate (10). An insulating layer (28) is provided on the bottom surface and an innernwall surface of the depression (22). A conductive portion (30) is provided inside theninsulating layer (28). A second surface (38) of the semiconductor substrate (10) isnetched by a first etchant having characteristics such that the etching amount with respectnto the semiconductor substrate (10) is greater than the etching amount with respect tonthe insulating layer (28), and the conductive portion (30) is caused to project whilencovered by the insulating layer (28). At least a portion of the insulating layer (28)nformed on the bottom surface of the depression (22) is etched with a second etchantnhaving characteristics such that at least the insulating layer (28) is etched withoutnforming a residue on the conductive portion (30), to expose the conductive portion (30). |