Variable Width Edge Trimming for Semiconductor Notch Processing
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Solution Overview
Problem
The manufacturing process of chips faces challenges with edge trimming, where the notch on the workpiece can be damaged or obscured, leading to increased device damage and crack generation during grinding, which complicates subsequent processing steps.
Innovation Solution
A processing apparatus and method that utilize a holding table, processing unit, and control unit to set an annular processing trajectory with a variable width, narrowing the processing width near the notch and maintaining a reference width further away, minimizing device damage and crack probability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the processing width of edge trimming is narrowed to reduce device damage, then the proportion of devices damaged by edge trimming is reduced, but the notch may remain on the front surface side and cracks may be generated during grinding
Solution Approach 1:
The patent applies local quality by making the processing width variable rather than uniform. Specifically, the processing width is set to be larger in the first range (notch region) and smaller in the second range (device region). This local differentiation allows the notch to be completely removed in the first range while minimizing damage to devices in the second range, thus resolving the contradiction between reducing device damage and preventing crack generation.
Solution Approach 2:
The patent employs dynamics by making the processing width adjustable and variable during the edge trimming process. The control unit dynamically changes the processing width based on the positional range, transitioning from a larger width in the notch region to a smaller width in the device region. This dynamic adjustment enables optimal removal of the notch while protecting devices, thereby resolving the contradiction.
2Object-affected harmful factors
If the processing width is increased to ensure complete removal of the notch, then crack generation during grinding is reduced, but more devices may be damaged by edge trimming
Solution Approach 1:
The patent applies local quality by differentiating the processing width across different spatial regions. In the first range corresponding to the notch position, a larger processing width is used to ensure complete removal and prevent cracks. In the second range corresponding to the device region, a smaller processing width is used to minimize device damage. This localized differentiation resolves the contradiction between notch removal effectiveness and device protection.
Solution Approach 2:
The patent employs dynamics by dynamically adjusting the processing width based on the current positional range during edge trimming. The control unit transitions the processing width from larger to smaller as the trimming progresses from the notch region to the device region, enabling optimal performance in both areas and resolving the contradiction.
3Productivity
If uniform processing width is used for edge trimming, then the processing is simple and efficient, but either the notch remains (causing cracks) or devices are damaged
Solution Approach 1:
The patent employs dynamics by making the processing width variable rather than static and uniform. The control unit dynamically adjusts the processing width based on the positional range, transitioning from a larger width in the notch region to a smaller width in the device region. This dynamic approach maintains high efficiency while ensuring complete notch removal and device protection, thereby resolving the contradiction with uniform processing.
Solution Approach 2:
The patent applies local quality by differentiating the processing parameters across different spatial regions. The processing width is locally optimized to be larger where the notch exists and smaller where devices are located, enabling effective notch removal and device protection simultaneously without significantly compromising overall processing efficiency.
Data Source
AI summary
A processing trajectory at the time of processing a peripheral part of a workpiece is set such that a processing width of the peripheral part of the workpiece is narrowed as spaced more from the position of a notch in a predetermined range centered at the position of the notch and that the processing width of the peripheral part of the workpiece is equal to a reference width (lower limit of the processing width) outside the predetermined range. As a result, the processing width at a position far from the position of the notch is narrow, and therefore, the proportion of devices damaged by edge trimming can be reduced or set to zero. In addition, since the processing width at the position of the notch is widened most, the probability that cracks are generated in the workpiece after the back surface side of the workpiece is ground can be lowered.