Ga2O3 Single Crystal Substrates: Fe Compensation for High Resistivity
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Solution Overview
Problem
Existing methods for producing Ga 2 O 3 single crystals with high resistivity face challenges in achieving the target impurity concentration without compromising crystal quality, particularly when using low-purity Ga 2 O 3 powder as a raw material, which contains trace amounts of Si as a donor impurity, leading to n-type conductivity.
Innovation Solution
A production method involving the growth of Ga 2 O 3 -based single crystals by adding Fe as an acceptor impurity at concentrations higher than the donor impurity concentration, using raw materials with purities of 99.999 mass% or 99.99 mass%, to achieve high resistivity while maintaining crystal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Ga2O3 powder with purity of 99.999 mass% is used as raw material, then the crystal quality is maintained, but the resistivity is low due to trace Si donor impurity
Solution Approach 1:
The patent converts the harmful effect of Si donor impurity (which causes n-type conductivity and low resistivity) by introducing Fe acceptor impurity that compensates for the Si doping effect. The Fe impurity acts as a beneficial counterbalance, transforming the unavoidable presence of Si into an opportunity to achieve high resistivity through acceptor-donor compensation mechanism.
Solution Approach 2:
The patent changes the chemical composition parameter by adding Fe impurity at controlled concentrations (0.01-0.5 at%) to alter the electrical properties of Ga2O3 crystal. This parameter change enables the crystal to transition from n-type conductivity to high-resistivity state while maintaining structural quality.
2Manufacturing precision
If high concentration of acceptor impurity is doped into Ga2O3 single crystal to increase resistivity, then the resistivity increases, but the crystal quality decreases
Solution Approach 1:
The patent optimizes the Fe impurity concentration parameter within a specific range (0.01-0.5 at%) to achieve the desired resistivity while preventing crystal quality degradation. This controlled parameter adjustment ensures that the acceptor doping level is sufficient to compensate Si donors but not so high as to cause structural defects or phase transformations.
Solution Approach 2:
The patent applies partial doping of Fe impurity rather than complete or excessive doping. By using Fe concentration that is just sufficient to compensate Si donors (achieving high resistivity), the patent avoids the harmful effects of excessive doping while still achieving the desired electrical properties.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method enables the production of high-resistivity Ga 2 O 3 -based single crystal substrates with suitable sizes for mass production, preventing a decrease in crystalline quality and allowing for cost-effective manufacturing.
Implementation Method 1
adding a Fe as an acceptor impurity at a concentration higher than a concentration of the donor impurity
Implementation Method 2
growing a Ga 2 O 3 -based single crystal
Data Source
Figure 1
AI summary
Provided are: a Ga2O3 single crystal substrate comprising a Ga2O3 single crystal which has been made to have a high resistance while inhibiting a reduction in the crystal quality thereof; and a production method therefor. According to one embodiment of the present invention, provided is a production method for a Ga2O3 single crystal substrate, said production method including: a step in which Fe is added to a Ga2O3 starting material, and a Ga2O3 single crystal (5) including Fe at a concentration higher than that of a donor impurity mixed therewith is grown from the Ga2O3 starting material; and a step in which a Ga2O3 single crystal substrate is cut from the Ga2O3 single crystal (5).