Composite Wafer Fabrication via Hydrogen Ion Implantation
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Solution Overview
Problem
The existing methods for manufacturing composite wafers, such as silicon on sapphire (SOS) wafers, face challenges with bonding quality due to roughness in the chamfered periphery and are inefficient in handling irregular wafer sizes, leading to high costs and time consumption.
Innovation Solution
A method involving bonding surfaces of at least two handle wafers with a donor wafer having a hydrogen ion implantation layer, followed by heating and detaching the film along the implantation layer to produce multiple composite wafers without the need for chamfering, allowing for the use of wafers with varying diameters and improving bonding strength through surface activation treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two-stage chamfering is performed on donor wafer and handle wafer, then bonding quality is improved, but manufacturing cost and time increase significantly
Solution Approach 1:
The invention extracts and eliminates the chamfering step from the manufacturing process. By using wafers with beveled edges that are directly bonded without requiring additional two-stage chamfering operations, the method removes this costly and time-consuming process step while maintaining bonding quality through the pre-formed beveled geometry
Solution Approach 2:
The beveled edges are prepared in advance during wafer fabrication rather than requiring post-fabrication chamfering. This preliminary formation of the bonding surface geometry allows direct bonding without additional processing steps, reducing both cost and time while ensuring proper bonding quality
2Area of stationary object
If donor wafer diameter is made slightly larger than handle wafer diameter, then bonding area is increased, but wafer size adaptability decreases due to SEMI standard limitations
Solution Approach 1:
The invention makes the donor wafer serve multiple functions: it provides a large bonding area for multiple handle wafers, acts as a template for various wafer sizes, and enables production of different composite wafer configurations. The beveled edge geometry and size relationship are designed to be universally applicable across different wafer diameter combinations, not limited to specific SEMI standard sizes
Solution Approach 2:
The large donor wafer is segmented to produce multiple composite wafers by bonding multiple handle wafers to different regions of the donor wafer. This segmentation approach allows one donor wafer to serve multiple purposes and produce multiple products, increasing both bonding area utilization and size adaptability
3Adaptability or versatility
If irregular sized wafers are used, then bonding area and flexibility are improved, but apparatus modification cost increases
Solution Approach 1:
The invention changes the size parameter relationship between donor and handle wafers from the conventional 'slightly larger' to 'significantly larger' (at least twice the diameter). This parameter change enables the donor wafer to accommodate multiple handle wafers of standard sizes without requiring apparatus modification, as the bonding process itself adapts to the size difference through the beveled edge geometry and bonding methodology
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 method enables the production of multiple composite wafers from a single donor wafer, omitting the costly and time-consuming chamfering step, while ensuring strong bonding and efficient film transfer, thus reducing production costs and enhancing the quality of the composite wafers.
Implementation Method 1
a hydrogen ion implantation layer formed inside thereof by implanting hydrogen ions from the surface of the donor wafer
Implementation Method 2
heating the bonded wafer at 200° C. to 400° C.
Data Source
AI summary
This invention provides a method for manufacturing composite wafers in which at least two composite wafers can be obtained from one donor wafer, and in which the chamfering step can be omitted. Provided is a method for manufacturing composite wafers comprising: bonding surfaces of at least two handle wafers and a surface of a donor wafer which has a diameter greater than or equal to a sum of diameters of the at least two handle wafers and which has a hydrogen ion implantation layer formed inside thereof by implanting hydrogen ions from the surface of the donor wafer, to obtain a bonded wafer; heating the bonded wafer at 200° C. to 400° C.; and detaching a film from the donor wafer along the hydrogen ion implantation layer of the heated bonded wafer, to obtain the composite wafers having the film transferred onto the at least two handle wafers.