SOI Substrate Backside Layering for Electrostatic Adsorption
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Solution Overview
Problem
The existing SOI substrates face difficulties in achieving electrostatic adsorption due to their high resistivity and insulation properties, making it challenging to manufacture semiconductor devices effectively.
Innovation Solution
A method of manufacturing a SOI substrate involves forming an insulating dielectric layer and an electrostatic adsorption layer on the second surface of the substrate, where the resistivity of the electrostatic adsorption layer is less than that of the substrate, enabling easier electrostatic adsorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the substrate resistivity is increased to improve insulation properties, then the electrostatic adsorption capability deteriorates
Solution Approach 1:
The substrate is segmented into two functional regions: a high-resistivity region (first region) providing insulation properties and a low-resistivity region (second region) enabling electrostatic adsorption. This segmentation allows the substrate to simultaneously achieve good insulation capability and electrostatic adsorption effect by assigning different electrical resistance characteristics to different spatial zones.
Solution Approach 2:
Different regions of the substrate are assigned different local electrical properties. The first region has high resistivity (greater than 1000Ω·cm) for insulation, while the second region has low resistivity (less than 1000Ω·cm) for electrostatic adsorption. This local differentiation of material properties resolves the contradiction between needing high insulation and high electrostatic adsorption capability.
2Reliability
If the substrate resistivity is increased to reduce parasitic capacitance, then the device manufacturing difficulty increases
Solution Approach 1:
The substrate is divided into a first region with high resistivity for reducing parasitic capacitance and a second region with low resistivity for facilitating device manufacturing. The area ratio of the first region to the second region is controlled between 1:1 and 10:1, optimizing both parasitic capacitance reduction and manufacturing ease.
Solution Approach 2:
Different local regions have different resistivity characteristics tailored to their specific functions. The high-resistivity first region minimizes parasitic capacitance effects, while the low-resistivity second region enables easier device fabrication and electrostatic adsorption, thus resolving the contradiction between parasitic capacitance reduction and manufacturing ease.
3Reliability
If a uniform high-resistivity substrate is used to improve insulation, then the electrostatic adsorption uniformity deteriorates
Solution Approach 1:
The substrate is segmented into a first region occupying 10%-90% of the total area with high resistivity for insulation, and a second region with low resistivity for electrostatic adsorption. This segmentation creates distinct functional zones that maintain both good insulation uniformity and electrostatic adsorption uniformity within their respective regions.
Solution Approach 2:
The substrate exhibits different electrical properties in different regions: the first region provides uniform high-resistivity insulation characteristics, while the second region provides uniform low-resistivity characteristics suitable for electrostatic adsorption. This local quality differentiation ensures both insulation uniformity and electrostatic adsorption uniformity are achieved in their respective functional zones.
Data Source
AI summary
A SOI substrate and a method of manufacturing a SOI substrate are provided. The method includes: providing a device wafer; wherein the device wafer includes a substrate, a buried oxide layer, and a semiconductor layer; the substrate has a first surface and a second surface opposite to the first surface; the buried oxide layer and the semiconductor layer are disposed sequentially on the first surface of the substrate; processing the substrate from the second surface of the substrate to sequentially form an insulating dielectric layer and an electrostatic adsorption layer; wherein a resistivity of the electrostatic adsorption layer is less than a resistivity of the substrate. The SOI substrate takes the electrostatic adsorption layer to perform electrostatic adsorption, difficulties of the SOI substrate performing the electrostatic adsorption are solved.