Device and process for heating III-V wafers, and annealed III-V semiconductor single crystal wafer
First Claim
1. A GaAs semiconductor single crystal wafer having a diameter of ≧
- 100 mm and a dislocation density of about ≦
1×
104 cm−
2,wherein said GaAs semiconductor single crystal wafer is semi-insulating (SI) and has a mean EL2 concentration of at least 1.4×
1016 cm−
3,wherein the surface of said GaAs semiconductor single crystal wafer has a number of light point defects (lpd), measured in an lpd size range of 0.3-2.0 μ
m, of smaller than about 0.3 cm−
2,wherein said GaAs semiconductor single crystal wafer is derived from Vertical Gradient Freeze (VGF)- or Vertical Bridgman (VB)-produced GaAs single crystal, andwherein a characteristic fracture strength, at which the wafer has a probability of failure of about 63.2% (Weibull characteristic strength σ
of test piece), is higher than about 1900 MPa.
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Abstract
A device for heat treating (annealing) a III-V semiconductor wafer comprises at least one wafer support unit which is dimensioned such that a cover provided above the wafer surface is either spaced without any distance or with a distance of maximally about 2 mm to the wafer surface. A process for heat treating III-V semiconductor wafers having diameters larger than 100 mm and a dislocation density below 1×104 cm−2 is carried out in the device of the invention. SI GaAs wafers produced have an at least 25% increased characteristic fracture strength (Weibull distribution), an improved radial macroscopic and mesoscopic homogeneity and an improved quality of the mechano-chemically polished surface. The characteristic fracture strength is higher than 1900 MPa.
49 Citations
5 Claims
-
1. A GaAs semiconductor single crystal wafer having a diameter of ≧
- 100 mm and a dislocation density of about ≦
1×
104 cm−
2,wherein said GaAs semiconductor single crystal wafer is semi-insulating (SI) and has a mean EL2 concentration of at least 1.4×
1016 cm−
3,wherein the surface of said GaAs semiconductor single crystal wafer has a number of light point defects (lpd), measured in an lpd size range of 0.3-2.0 μ
m, of smaller than about 0.3 cm−
2,wherein said GaAs semiconductor single crystal wafer is derived from Vertical Gradient Freeze (VGF)- or Vertical Bridgman (VB)-produced GaAs single crystal, and wherein a characteristic fracture strength, at which the wafer has a probability of failure of about 63.2% (Weibull characteristic strength σ
of test piece), is higher than about 1900 MPa. - View Dependent Claims (2, 3, 4, 5)
- 100 mm and a dislocation density of about ≦
Specification