Semiconductor Wafer Slicing with Controlled Wire Reciprocation
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Solution Overview
Problem
Conventional methods for manufacturing semiconductor wafers using wire saws generate long period waviness, which cannot be effectively removed by existing polishing processes, necessitating the inclusion of lapping or double disk grinding steps, and also struggle with removing short period waviness due to limitations in polishing cloth hardness and capability.
Innovation Solution
The method involves slicing semiconductor wafers using a wire saw with a reciprocating wire speed of 3 to 8 cycles per minute to convert long period waviness into short period waviness, followed by a polishing process using a fixed abrasive grain polishing cloth with no loose abrasive grains to completely remove waviness, thereby omitting the need for lapping or double disk grinding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If lapping or double disk grinding processes are included, then long period waviness can be removed, but manufacturing complexity and process time increase
Solution Approach 1:
The invention extracts and eliminates the lapping or double disk grinding processes from the manufacturing sequence. By optimizing the wire saw slicing parameters beforehand, the need for these intermediate complex processes is completely removed, simplifying the manufacturing flow.
Solution Approach 2:
The invention performs preliminary action by optimizing the slicing parameters during the wire saw process itself. The reciprocating speed and number of reciprocations are controlled in advance to prevent long period waviness formation, so that no subsequent lapping or grinding is needed.
2Manufacturing precision
If wire reciprocating speed is increased to convert long period waviness to short period waviness, then polishing effectiveness improves, but wire saw operation complexity increases
Solution Approach 1:
The invention establishes specific parameter ranges for wire reciprocating speed (3-8 cycles per minute) and number of reciprocations. These standardized parameter changes make the operation straightforward while effectively converting long period waviness to short period waviness that can be removed by polishing.
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 removes both long and short period waviness from the wafer surface during the polishing process, allowing for the production of high-quality semiconductor wafers without the need for additional grinding steps, improving form accuracy and reducing manufacturing complexity.
Implementation Method 1
slicing a work by using a wire saw, wherein the wire is reciprocated at predetermined constant cycles of 3 or more and less than 8 per a minute
Implementation Method 2
the wafer surface is polished while the wafer is rotated, by using a fixed abrasive grain polishing cloth, in which an abrasive grain is fixed, and a polishing liquid
Data Source
Figure 1
Figure 2A~2C
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AI summary
In order to omit a lapping process or a double disk grinding process by performing slicing operation(S1) so as not to generate long period waviness (L2) on the surface of the wafer (W) in a slicing process and by completely removing short period waviness (L1) remaining in the surface of the sliced wafer (W) during a polishing process, there is provided a manufacturing method including a slicing process of slicing a semiconductor wafer by reciprocating a wire of a wire saw at constant cycles of 3 or more and less than 8 per a minute (S1), a grinding process of grinding both sides of the sliced wafer by a grinding wheel, one-side by one-side (S3), and a polishing process of performing a chemical mechanical polishing on both sides of the ground wafer (W) by a fixed abrasive grain polishing cloth (S6), in which an abrasive grain is fixed, and a abrasive containing no abrasive grains.