Regenerated Layer Transferred Wafer Process
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Solution Overview
Problem
Conventional processes for regenerating layer transferred wafers are time-consuming and reduce the number of regeneration times due to the need for chamfering or etching to remove ion implanted layers, leading to increased processing costs and surface roughness.
Innovation Solution
A process where ions are implanted only into the main flat portion of a semiconductor wafer, forming a laminated body with a ring-shape step, allowing for separation without generating steps in the periphery, thus omitting chamfering or etching, and subsequent polishing to reduce processing time and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chamfering or etching is performed to remove ion implanted layer from step periphery, then particle generation is prevented and surface roughness is reduced, but processing time increases and number of regeneration times decreases
Solution Approach 1:
The invention performs preliminary action by forming a ring-shaped step structure before ion implantation, positioning the implantation area to exclude the periphery where steps form during separation. This prevents the need for subsequent chamfering or etching operations, thereby maintaining surface quality while improving regeneration efficiency
Solution Approach 2:
The invention segments the wafer surface into an ion-implanted area and a non-implanted peripheral area by using the ring-shaped step structure. This segmentation allows the ion implantation to be confined to the central region, preventing ion implanted layer formation at the periphery where steps occur, thus eliminating the need for removal operations
2Reliability
If conventional regeneration process with chamfering and etching is used, then ion implanted layer is removed, but processing cost increases
Solution Approach 1:
The ring-shaped step structure is formed in advance before ion implantation, pre-positioning the implantation boundaries to prevent ion layer formation at step locations. This eliminates subsequent costly removal operations while ensuring surface quality
Solution Approach 2:
The invention extracts or excludes the periphery region from ion implantation by using the ring-shaped step as a boundary. This prevents ion implanted layer formation in the peripheral step areas, eliminating the need for expensive removal processes while maintaining necessary surface quality
3Manufacturing precision
If ion implantation is performed on entire wafer surface, then uniform implantation is achieved, but step periphery contains ion implanted layer requiring removal
Solution Approach 1:
The invention applies local quality by confining ion implantation to specific regions (central area within ring-shaped step) rather than treating the entire wafer surface uniformly. This localized approach prevents ion layer formation at peripheral steps, simplifying the overall process while maintaining implantation precision where needed
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 reduces processing time, decreases regeneration costs, and increases the number of regeneration times by eliminating the need for chamfering or etching, while ensuring high flatness and reusability of wafers, resulting in a more efficient and cost-effective method for producing SOI wafers.
Implementation Method 1
forming an ion implanted area within the semiconductor wafer by implanting ions only into the main flat portion
Implementation Method 2
separating the semiconductor wafer in the ion implanted area from a thin layer by heat treatment of the laminated body
Data Source
AI summary
A processing time required for regeneration of a layer transferred wafer is reduced and the regeneration cost is lowered, while a removal amount at the regeneration is decreased the number of regeneration times is increased. A main surface of a semiconductor wafer (13) has a main flat portion (13d) and a chamfered portion (13c) formed in the periphery of the main flat portion (13d), an ion implanted area (13b) is formed by implanting ions only into the main flat portion (13d), a laminated body (16) is formed by laminating the main flat portion (13d) on a main surface of a support wafer (14), and moreover, the semiconductor wafer (13) is separated from a thin layer (17) in the ion implanted area (13b) by heat treatment at a predetermined temperature so as to obtain a thick layer transferred wafer (12), which is to be regenerated. The main flat portion (13d) of the semiconductor wafer (13) is formed to have a ring-shape step (13e) protruding from the chamfered portion (13c), and the semiconductor wafer (13) is separated from the thin layer (17) on the whole surface of the ion implanted area (13b) so that no step is generated in the periphery thereby to obtain the layer transferred wafer (12).