Semiconductor device and its manufacturing method
First Claim
1. A manufacturing method of a semiconductor device having a single-crystal substrate made of a material different from nitride III-V compound semiconductors and a first device made on a first surface of the single-crystal substrate by using III-V compound semiconductors, in which electrical connection to the first device is made through a via hole formed in the single-crystal substrate, comprising the step of:
- forming the via hole by selectively etching a second surface of the single-crystal substrate by using an etchant containing phosphoric acid or phosphoric acid and sulfuric acid heated to 150 through 450°
C.
0 Assignments
0 Petitions
Accused Products
Abstract
After making a GaN FET by growing GaN semiconductor layers on the surface of a sapphire substrate, the bottom surface of the sapphire substrate is processed by lapping, using an abrasive liquid containing a diamond granular abrasive material and reducing the grain size of the abrasive material in some steps, to reduce the thickness of the sapphire substrate to 100 μm or less. Thereafter, the bottom surface of the sapphire substrate is processed by etching using an etchant of phosphoric acid or phosphoric acid/sulfuric acid mixed liquid to remove a strained layer by lapping followed by making a via hole by etching the bottom surface of the sapphire substrate by using a similar etchant.
-
Citations
11 Claims
-
1. A manufacturing method of a semiconductor device having a single-crystal substrate made of a material different from nitride III-V compound semiconductors and a first device made on a first surface of the single-crystal substrate by using III-V compound semiconductors, in which electrical connection to the first device is made through a via hole formed in the single-crystal substrate, comprising the step of:
forming the via hole by selectively etching a second surface of the single-crystal substrate by using an etchant containing phosphoric acid or phosphoric acid and sulfuric acid heated to 150 through 450°
C.- View Dependent Claims (2, 3, 4, 5, 6)
-
7. A manufacturing method of a semiconductor device having a single-crystal substrate made of a material different from nitride III-V compound semiconductors and a first device made on a first surface of the single-crystal substrate by using III-V compound semiconductors, in which electrical connection to the first device is made through a via hole formed in the single-crystal substrate, comprising the steps of:
-
making a hole as deep as 10 μ
m or more but not reaching the first surface of the substrate by selectively irradiating laser light having a wavelength not shorter than 6 μ
m onto a second surface of the single-crystal substrate; and
making the via hole by etching the second surface of the single-crystal substrate by using an etchant containing phosphoric acid or phosphoric acid and sulfuric acid heated to 150 through 450°
C. so as to make the hole reach the first surface of the substrate.- View Dependent Claims (8, 9, 10, 11)
-
Specification