Composite Structure Thinning via Zone of Weakening Profile
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Solution Overview
Problem
The existing process for manufacturing composite structures, such as silicon-on-insulator types, faces challenges in controlling the thickness uniformity of the thinned working layer, which can vary by more than 10 Å due to nonuniform partial oxidation, making precise thickness control difficult.
Innovation Solution
A process that forms a zone of weakening in the donor substrate through nonuniform implantation of species like hydrogen or helium, allowing for a thickness profile compensation during the thinning stage, resulting in a substantially uniform thinned working layer thickness by adjusting the dose of implanted species across the zone of weakening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If partial oxidation is used to thin the working layer, then the thinning process can be achieved, but the thickness uniformity deteriorates with variations exceeding 10 Å
Solution Approach 1:
The patent applies preliminary action by forming a zone of weakening with a specific thickness profile before the thinning process. This pre-formed profile compensates for the nonuniform oxidation that will occur during thinning, ensuring that the final thinned layer achieves uniform thickness. The zone of weakening is created with varying implantation doses to predictably counteract the expected nonuniform consumption during oxidation.
Solution Approach 2:
The patent implements local quality by creating a zone of weakening with spatially varying properties. The implantation dose is nonuniform across the zone, with different regions having different concentrations of implanted species. This local variation in the zone's properties allows different parts of the working layer to be thinned at different rates during oxidation, ultimately achieving overall uniformity.
2Manufacturing precision
If uniform implantation dose is used in the zone of weakening, then the process is simple, but the thickness profile cannot compensate for nonuniform thinning
Solution Approach 1:
The patent applies parameter changes by varying the implantation dose parameter across the zone of weakening. Instead of using a uniform dose, the dose is modified as a function of position, creating a gradient or specific spatial distribution. This parameter variation enables the zone to produce the compensating thickness profile needed to offset nonuniform thinning during subsequent oxidation processes.
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 compensates for nonuniformity in the thinning stage, achieving a substantially constant thickness profile of the thinned working layer, reducing variations to within +/−5 Å as required for silicon-on-insulator structures.
Implementation Method 1
forming a zone of weakening in the donor substrate through nonuniform implantation of species like hydrogen or helium
Implementation Method 2
the thinning stage e) generally comprises a stage of partial oxidation of the working layer 5, followed by a withdrawal of the oxidized part of the working layer 5
Data Source
AI summary
A process for the manufacture of a composite structure includes the following stages: a) providing a donor substrate comprising a first surface and a support substrate; b) forming a zone of weakening in the donor substrate, the zone of weakening delimiting, with the first surface of the donor substrate, a working layer; c) assembling the support substrate and the donor substrate; d) fracturing the donor substrate along the zone of weakening; and e) thinning the working layer so as to form a thinned working layer. Stage b) is carried out so that the working layer exhibits a thickness profile appropriate for compensating for the nonuniformity in consumption of the working layer during stage e).