Semiconductor Substrate Backside Texturing for Lithographic Distortion
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Solution Overview
Problem
The backside of semiconductor substrates in integrated circuit manufacturing becomes contaminated and uneven, leading to significant distortion during chucking on imaging scanners, which affects the alignment of lithographic layers and overall performance.
Innovation Solution
Texturizing the backside of semiconductor substrates to create a uniform coefficient of friction, using chemical etching, plasma processing, or laser treatment to improve slippage uniformity across chuck pins, thereby reducing distortion during the lithographic process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the backside of semiconductor substrates is left smooth and clean, then manufacturing simplicity is maintained, but significant distortion occurs during chucking on imaging scanners
Solution Approach 1:
The backside of the semiconductor substrate is texturized in advance before the substrate enters the lithography tool. This preliminary texturing creates a controlled surface structure that prevents distortion during chucking, eliminating the need for complex real-time distortion compensation while maintaining manufacturing precision
Solution Approach 2:
Texturing is applied specifically to the backside surface of the substrate that contacts the chuck pins, while the front side and other surfaces remain unaffected. This localized treatment addresses the distortion problem at the contact interface without adding unnecessary complexity to the entire substrate or manufacturing process
2Manufacturing precision
If chemical etching is used to texturize the backside, then slippage uniformity improves, but processing time and chemical usage increase
Solution Approach 1:
The texturing process utilizes controlled chemical etching parameters (etchant concentration, temperature, etch time) to create the desired surface morphology. By optimizing these parameters, uniform slippage characteristics are achieved while minimizing processing time and chemical consumption through precise control of the etching rate and depth
3Manufacturing precision
If the backside surface is made rough to reduce friction, then overlay performance improves, but contamination resistance decreases
Solution Approach 1:
The texturing creates a controlled roughness pattern that provides low-friction characteristics for improved overlay performance. The specific geometry and scale of the texturing are designed to maintain contamination resistance while achieving the desired slippage uniformity, balancing both requirements through localized surface modification
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 texturization of the substrate backside results in more uniform wafer distortion signatures and improved overlay performance by minimizing the coefficient of friction, enhancing the precision and accuracy of lithographic layer alignment.
Implementation Method 1
using chemical etching, plasma processing, or laser treatment to improve slippage uniformity
Implementation Method 2
using chemical etching, plasma processing, or laser treatment to improve slippage uniformity
Implementation Method 3
using chemical etching, plasma processing, or laser treatment to improve slippage uniformity
Data Source
AI summary
Embodiments described relate to a method and apparatus for reducing lithographic distortion. A backside of a semiconductor substrate may be texturized. Then a lithographic process may be performed on the semiconductor substrate having the texturized backside.