Substrate Grinding with Heated Etchant for Low-Roughness Wafers
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Solution Overview
Problem
Conventional substrate grinding methods cause surface damage and increased roughness, leading to higher current leakage and device failure in semiconductor substrates, necessitating additional processing steps and increased costs.
Innovation Solution
A substrate grinding tool that combines mechanical grinding with a heated chemical etchant, such as potassium hydroxide, to enhance the grinding rate and reduce surface roughness, using a controlled environment to optimize the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional mechanical grinding is used to remove material from semiconductor substrate, then material removal is achieved, but surface damage and increased roughness occur
Solution Approach 1:
The patent combines mechanical grinding with chemical etching in a hybrid process. The mechanical grinding wheel removes material while a chemical etchant (such as KOH solution) simultaneously etches the substrate surface. This combination allows for higher material removal rates while the chemical component smooths the surface, reducing roughness and damage compared to pure mechanical grinding.
Solution Approach 2:
The patent applies parameter changes by controlling the temperature, concentration, and flow rate of the chemical etchant during the grinding process. By optimizing these parameters, the chemical etching component effectively reduces surface roughness while maintaining high material removal efficiency, resolving the contradiction between productivity and manufacturing precision.
2Productivity
If conventional mechanical grinding is used to reduce substrate thickness, then throughput is maintained, but surface damage increases leading to device failure
Solution Approach 1:
The hybrid mechanical-chemical grinding process merges the high throughput capability of mechanical grinding with the surface-quality enhancing effect of chemical etching. This combination removes material efficiently while simultaneously reducing surface damage that would otherwise lead to device failure, thereby maintaining productivity while improving reliability.
Solution Approach 2:
The patent converts the potentially harmful effect of mechanical stress and surface damage from conventional grinding into a benefit by introducing chemical etching. The chemical etchant selectively removes damaged surface layers and smooths the substrate, transforming the harmful surface damage into an opportunity for surface refinement, thus reducing device failure rates.
3Device complexity
If conventional mechanical grinding is used, then simple process equipment is required, but additional processing steps are needed to correct surface damage
Solution Approach 1:
The patent merges material removal and surface finishing operations into a single hybrid grinding process. Instead of requiring separate mechanical grinding followed by additional surface treatment steps, the combined mechanical-chemical process achieves both objectives simultaneously, reducing total processing time and eliminating the need for multiple sequential operations.
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 combined method increases throughput, reduces surface damage, and minimizes roughness, thereby decreasing the likelihood of device failure and the need for additional processing, thus lowering manufacturing complexity and cost.
Implementation Method 1
a chemical etchant, such as potassium hydroxide, heated to a high temperature is used to chemically etch the semiconductor substrate
Implementation Method 2
The chemical etchant may include a silicon etchant that is heated to a high temperature, which may increase the etch rate of the chemical etchant
Data Source
AI summary
A substrate grinding tool is configured to remove material from a semiconductor substrate in a grinding operation. In the grinding operation, the substrate grinding tool uses a combination of mechanical grinding and a chemical etchant to remove material from the semiconductor substrate. The chemical etchant may be heated to a high temperature, which may increase the etch rate of the chemical etchant. The use of the combination of mechanical grinding and the chemical etchant may increase the grinding rate of the substrate grinding tool for grinding semiconductor substrates, may reduce surface roughness for semiconductor substrates that are processed by the substrate grinding tool, and/or may reduce surface damage for semiconductor substrates that are processed by the substrate grinding tool, among other examples.