Strained Diamond Doping via CVD Relaxation Layer
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Solution Overview
Problem
Current methods for n-type doping of diamond semiconductors, such as phosphorus doping, result in high resistivity and low electron mobility due to high formation energy and low doping concentrations, making it difficult to achieve effective n-type performance.
Innovation Solution
A chemical vapor deposition (CVD) method that applies a strain to the diamond by growing an XaC1-a gradient buffer layer and an XbC1-b relaxation layer, followed by doping, to reduce the formation energy of dopants and enhance doping concentration and electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If phosphorus doping is used to achieve n-type diamond, then the diamond can be doped, but the doping concentration is low and resistivity is high due to high formation energy
Solution Approach 1:
The patent applies biaxial stretching strain to the diamond lattice, changing the physical state of the crystal structure. This strain modifies the lattice constant and reduces the formation energy of phosphorus dopants, enabling higher doping concentrations while maintaining electrical performance. The strained state creates favorable conditions for phosphorus incorporation that overcome the inherent high formation energy barrier.
Solution Approach 2:
The patent introduces a strained buffer layer before the diamond growth stage. This preliminary strained layer prepares the substrate with the appropriate lattice structure and strain state, creating favorable conditions for subsequent phosphorus doping. The strain is pre-applied to the buffer layer, which then transfers to the diamond layer, facilitating easier dopant incorporation.
2Reliability
If co-doping is used to reduce ionization energy, then electrical performance improves, but the formation energy of co-doped structure remains high making it difficult to achieve
Solution Approach 1:
By applying biaxial stretching strain to the diamond lattice, the patent changes the physical parameters of the crystal structure. This strain reduces the formation energy barrier for co-doping, making it feasible to achieve multi-element doping configurations that would otherwise be impossible. The strained state creates energetic conditions that favor the incorporation of multiple dopant elements simultaneously.
3Reliability
If other single-doped elements such as oxygen, sulfur and arsenic are used, then n-type doping is achieved, but the formation energy is high restraining electrical performance
Solution Approach 1:
The patent applies biaxial stretching strain to modify the diamond lattice parameters. This strain reduces the formation energy of various n-type dopants including oxygen, sulfur, and arsenic, making their incorporation more favorable. The strained lattice structure creates lower energy barriers for these dopants to integrate into the diamond crystal, thereby improving both doping concentration and electrical performance.
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 improves doping concentration and reduces resistivity by applying biaxial stretching strains, allowing for easier n-type doping and enhanced electrical performance of diamond semiconductors.
Implementation Method 1
growing an XaC1-a gradient buffer layer by CVD; introducing a mixed gas of a gas containing an element X, a methane gas and hydrogen
Implementation Method 2
a lattice constant of the XbC1-b relaxation layer is greater than a diamond lattice constant of the CVD strained diamond layer, so that the CVD strained diamond layer is in a stretching strain state
Data Source
AI summary
The present disclosure relates to a method for growing and doping a strained diamond based on a chemical vapor deposition (CVD) method. The method comprises: depositing a gradient buffer layer and a relaxation layer on a substrate layer in sequence by the CVD method; and finally, depositing a CVD strained diamond layer on the relaxation layer and performing doping by the CVD method. According to the method, a lattice constant of the relaxation layer prepared by utilizing the CVD method is greater than a lattice constant of the diamond, so that a diamond generates a stretching strain. In growing and doping processes, the CVD strained diamond is in a stretching strain state. Therefore, a formation energy of a doped element is low, and it is easy to dope the diamond, so that a doping concentration of the diamond is high.