Diamond Heterostructure Sacrificial Layers for Crack-Free Wafer Separation
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Solution Overview
Problem
Producing large diameter diamond wafers with high quality and minimal waste is challenging due to issues with thermal stress, cracking, and material loss during cutting processes like laser cutting.
Innovation Solution
A method involving the formation of a diamond heterostructure using epitaxial growth of sacrificial layers made of niobium nitrate and/or titanium nitride, followed by the growth of diamond layers, and subsequent separation of diamond wafers using a gas etch like xenon difluoride.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional laser cutting is used to produce large diameter diamond wafers, then wafer separation can be achieved, but thermal stress and cracking occur causing high damage rates
Solution Approach 1:
A sacrificial layer is deposited on the diamond substrate before wafer separation. This preliminary action creates a weak plane that enables clean separation without direct laser cutting of the diamond, preventing thermal stress and cracking while maintaining wafer integrity
Solution Approach 2:
The sacrificial layer acts as an intermediary between the diamond layers. It provides a controlled separation interface that eliminates the need for direct mechanical or thermal cutting of the diamond material, thereby preventing damage while enabling productive wafer separation
2Productivity
If traditional cutting methods are used to separate diamond wafers, then separation can be achieved, but significant material loss occurs
Solution Approach 1:
The sacrificial layer is extracted or removed after serving its separation function. This allows the diamond wafers to be separated without cutting through the diamond material itself, eliminating material loss while maintaining high productivity
Solution Approach 2:
The sacrificial layer serves as a temporary intermediary that facilitates wafer separation. Once the separation function is complete, the sacrificial layer is removed, leaving the diamond wafers intact with minimal to no material loss
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
This method enables the production of large diameter diamond wafers without cracking or significant damage, achieving high quality and minimizing material loss, thus overcoming the limitations of traditional cutting methods.
Implementation Method 1
A sacrificial layer is deposited on a diamond substrate. The sacrificial layer includes niobium nitrate (NbN) and/or titanium nitride (TiN). The sacrificial layer may be deposited using atomic-layer deposition, physical vapor deposition, chemical vapor deposition, and/or other deposition techniques.
Implementation Method 2
The sacrificial layer may be deposited using atomic-layer deposition, physical vapor deposition, chemical vapor deposition, and/or other deposition techniques.
Implementation Method 3
The sacrificial layer may be deposited using atomic-layer deposition, physical vapor deposition, chemical vapor deposition, and/or other deposition techniques.
Implementation Method 4
Illustrative embodiments use a gas etch to etch away at least a portion of a given sacrificial layer. The gas etch preferably comprises xenon difluoride.
Implementation Method 5
Illustrative embodiments use a gas etch to etch away at least a portion of a given sacrificial layer. The gas etch preferably comprises xenon difluoride.
Data Source
AI summary
A method manufactures a diamond heterostructure and separates diamond wafers from the heterostructure. The method provides a single-crystal substrate. A first single-crystal sacrificial layer is epitaxially formed on the base. The first sacrificial layer includes niobium nitrate and/or titanium nitride. A first single-crystal diamond layer is epitaxially formed on the first sacrificial layer. A second single-crystal sacrificial layer is epitaxially formed on the first diamond layer. The second sacrificial layer includes niobium nitrate and/or titanium nitride. A second single-crystal diamond layer is epitaxially formed on the second sacrificial layer.