Wafer Repair by Replacing Defective Device Regions Before Lamination
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Solution Overview
Problem
The manufacturing of laminated device chips is hindered by the presence of defective semiconductor devices in wafers, leading to a significant decrease in yield due to the need to discard entire chips even when only some devices are defective.
Innovation Solution
A method involving the removal of defective device regions from wafers using a laser beam, followed by fitting non-defective device chips into the removed regions, allowing for the creation of wafers without defective devices and subsequent laminated device chips that minimize yield loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wafers including defective devices are used to manufacture laminated device chips, then the manufacturing process can proceed without additional steps, but the yield of non-defective chips decreases significantly
Solution Approach 1:
The patent extracts defective device regions from wafers before lamination by applying laser beams along streets surrounding defective devices, creating through holes that are then filled with non-defective device chips. This extraction process removes the harmful defective devices from the manufacturing flow, allowing the rest of the wafer to be used for producing high-yield laminated device chips.
Solution Approach 2:
The patent performs preliminary inspection and removal of defective device regions before the lamination process. By conducting the removing step prior to forming the laminated wafer, the system prevents defective devices from contaminating the entire lamination batch, thereby preserving yield while maintaining manufacturing efficiency.
2Reliability
If defective device regions are removed from wafers using laser beams, then yield of non-defective chips is improved, but the device complexity and process steps increase
Solution Approach 1:
The patent replaces traditional mechanical cutting or chemical etching methods with laser beam processing for removing defective device regions. The laser beam system provides precise, contactless removal of defective regions along street patterns, reducing mechanical complexity while improving precision and yield.
Solution Approach 2:
The laser beam system serves multiple functions: it inspects for defective devices, defines removal boundaries along streets, and creates through holes for filling. This multi-functionality consolidates multiple process steps into a single versatile tool, reducing overall process complexity despite adding the laser step.
3Reliability
If non-defective device chips are fitted into through holes created by removing defective regions, then the number of non-defective laminated device chips increases, but the manufacturing time and process steps increase
Solution Approach 1:
The patent merges the removal of defective regions and the fitting of non-defective device chips into an integrated process flow. The through holes created by laser removal are immediately filled with non-defective device chips from the same or different wafers, combining two operations into a seamless sequence that minimizes idle time and accelerates the overall manufacturing cycle.
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 approach effectively reduces the number of defective laminated device chips produced, thereby enhancing the yield of non-defective chips by isolating and removing defective devices from the wafer manufacturing process.
Implementation Method 1
The removing step applies a laser beam along streets surrounding the semiconductor device determined to be a defective product
Data Source
AI summary
A wafer manufacturing method includes a wafer preparing step of preparing a wafer including a semiconductor device formed in each of a plurality of regions demarcated by a plurality of streets intersecting each other, a removing step of separating, from the wafer, a defective device region including a semiconductor device determined to be a defective product among a plurality of the semiconductor devices formed in the wafer, and a fitting step of fitting, into a through hole formed by separating the defective device region from the wafer, a device chip including a semiconductor device as a non-defective product having same functions as those of the semiconductor device determined to be a defective product and having a size capable of being fitted into the through hole.