US 12,742,259 B2 · Semi-insulating gallium arsenide single-crystal substrate, substrate with epitaxial layer, and method for manufacturing semi-insulating gallium arsenide single-crystal

Abstract

The semi-insulating gallium arsenide single-crystal substrate has a circular-shaped first main surface, in which a diameter of the semi-insulating gallium arsenide single-crystal substrate is 95 mm or more and 205 mm or less, a coefficient of light absorption of the semi-insulating gallium arsenide single-crystal substrate, with respect to near-infrared light at a wavelength of 940 nm, is 1.5 cm−1 or less, the number of etch pits per square centimeter, formed on the first main surface, in an etching test with immersion of the semi-insulating gallium arsenide single-crystal substrate in molten potassium hydroxide at 500° C. for 10 minutes is 300 or less, and a specific resistance of the semi-insulating gallium arsenide single-crystal substrate, as measured at 25° C. according to the Van der Pauw method, is 1.0×108 Ω·cm or more.

Claims11

Dependent claims

A semi-insulating gallium arsenide single-crystal substrate having a circular-shaped first main surface, wherein

a diameter of the semi-insulating gallium arsenide single-crystal substrate is 95 mm or more and 205 mm or less,
a coefficient of light absorption of the semi-insulating gallium arsenide single-crystal substrate, with respect to near-infrared light at a wavelength of 940 nm, is 1.5 cm−1 or less,
the number of etch pits per square centimeter, formed on the first main surface, in an etching test with immersion of the semi-insulating gallium arsenide single-crystal substrate in molten potassium hydroxide at 500° C. for 10 minutes is 300 or less, and
a specific resistance of the semi-insulating gallium arsenide single-crystal substrate, as measured at 25° C. in Hall measurement according to the Van der Pauw method, is 1.0×108 Ω·cm or more.

1 more element

A method for manufacturing a semi-insulating gallium arsenide single crystal by use of a vertical boat method, the manufacturing method comprising

preparing a single crystal growth apparatus including at least a cylindrical crucible and a heating element that heats the crucible,
providing a seed crystal at a bottom portion of the crucible and providing gallium arsenide bulk at an upper portion as compared with the seed crystal in the crucible,
heating the crucible by the heating element to partially melt the gallium arsenide and the seed crystal, thereby not only obtaining a gallium arsenide melt, but also contacting the gallium arsenide melt and a residue of the seed crystal, and
growing a crystal on the seed crystal in the gallium arsenide melt to obtain a semi-insulating gallium arsenide single crystal, wherein
the obtaining a semi-insulating gallium arsenide single crystal is carried out with a relationship among the following formula 4, formula 5 and formula 6 being satisfied:
0.2
°
⁢
C
.
/
⁢
mm
≤
X
≤
0.3
°
⁢
C
.
/
⁢
mm
Formula
⁢
4
X
+
0.0012
°
⁢
C
.
/
⁢
mm
2
×
Y
≤
Z
⁢
1
≤
X
+
0.0024
°
⁢
C
.
/
mm
2
×
Y
Formula
⁢
5
0.26
°
⁢
C
.
/
⁢
mm
≤
Z
⁢
2
≤
0.42
°
⁢
C
.
/
mm
Formula
⁢
6
wherein, in the formula 4, formula 5 and formula 6,
X represents a temperature gradient along an axial direction of the crucible, as measured with, as a center, an interface between the crystal and the gallium arsenide melt, and a unit of the temperature gradient is C/mm,
Y represents a distance from the interface to a first reference point in the crystal, and a unit of the distance is mm,
Z1 represents a temperature gradient along an axial direction of the crucible, as measured with the first reference point as a center, and a unit of the temperature gradient is ° C./mm, and
Z2 represents a temperature gradient along an axial direction of the crucible, as measured with, as a center, the first reference point at a distance from the interface to the first reference point, of 50 mm, and a unit of the temperature gradient is ° C./mm.

85 more elements

Dependencies are inferred from the claim text.

Semi-insulating gallium arsenide single-crystal substrate, substrate with epitaxial layer, and method for manufacturing semi-insulating gallium arsenide single-crystal

Life of this patent

Semi-insulating gallium arsenide single-crystal substrate, substrate with epitaxial layer, and method for manufacturing semi-insulating gallium arsenide single-crystal

Life of this patent

Abstract

Claims11