Crystalline Silicon Oxide SOI Structure Without Ion Implantation
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Solution Overview
Problem
Conventional methods for forming silicon-on-insulator (SOI) structures using ion implantation and oxygen deposition can adversely affect the quality of the remaining silicon layer, leading to suboptimal device performance.
Innovation Solution
A method involving a crystalline silicon substrate with a clean deposition surface, heated to an oxidation temperature of 550 to 1200°C, and exposed to molecular oxygen at pressures between 1·10−8 to 1·10−4 mbar, allowing oxygen to adsorb and diffuse into the substrate, forming a crystalline silicon oxide layer between the silicon base and top layers, thereby creating a high-quality SOI structure without additional deposition steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ion implantation is used to form silicon oxide layer, then the insulator layer is formed, but the quality of the remaining silicon layer deteriorates
Solution Approach 1:
The patent replaces the mechanical ion implantation process with a chemical oxidation process. Instead of bombarding the silicon surface with oxygen ions, molecular oxygen is supplied to the heated silicon surface, allowing oxidation to occur through chemical reaction and diffusion. This substitution eliminates the mechanical damage caused by ion bombardment while achieving the same insulator layer formation goal.
Solution Approach 2:
The patent changes the oxidation parameters by using molecular oxygen instead of oxygen ions, and by controlling the oxidation temperature (550-1200°C) and oxygen pressure (1·10⁻⁸ to 1·10⁻⁴ mbar). These parameter changes enable the formation of crystalline silicon oxide without the damaging effects of ion implantation, thereby improving silicon layer quality while maintaining insulator layer functionality.
2Reliability
If conventional oxygen deposition is used, then the oxidation process is achieved, but additional deposition steps are required
Solution Approach 1:
The patent merges the oxidation process with the existing vacuum chamber environment, eliminating the need for separate deposition steps. By supplying molecular oxygen directly in the vacuum chamber where the silicon substrate is already positioned and heated, the oxidation process is integrated into the existing manufacturing sequence, reducing process complexity while maintaining reliable oxidation.
3Manufacturing precision
If high oxidation temperature is used, then oxygen diffusion into silicon is enhanced, but energy consumption increases
Solution Approach 1:
The patent optimizes the oxidation temperature range (550-1200°C) to achieve effective oxygen diffusion while managing energy consumption. By controlling both the temperature and oxygen pressure parameters simultaneously, the process achieves sufficient diffusion without requiring excessively high temperatures, thereby balancing manufacturing precision with energy efficiency.
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 results in a high-quality SOI structure with a crystalline silicon oxide layer, enhancing the insulating barrier and reducing surface recombination of charge carriers, suitable for various semiconductor devices and applications.
Implementation Method 1
oxygen supplied into the vacuum chamber is adsorbed onto the deposition surface and diffuses into the silicon substrate
Implementation Method 2
oxygen supplied into the vacuum chamber is adsorbed onto the deposition surface and diffuses into the silicon substrate
Implementation Method 3
heating the silicon substrate to an oxidation temperature To in the range of 550 to 1200° C.
Data Source
AI summary
A method for forming a semiconductor structure comprising a silicon-on-insulator layer structure with crystalline silicon oxide SiOx as the insulator material comprises: providing a crystalline silicon substrate having a substantially clean deposition surface in a vacuum chamber; heating the silicon substrate to an oxidation temperature To in the range of 550 to 1200 ° C.; supplying, while keeping the silicon substrate in the oxidation temperature, with an oxidation pressure Po in the range of 1·10−8 to 1·10−4 mbar in the vacuum chamber, molecular oxygen O2 into the vacuum chamber with an oxygen dose Do in the range of 0.1 to 1000 Langmuir; whereby a crystalline silicon oxide layer with a thickness of at least two molecular layers is formed within the silicon substrate, between a crystalline silicon base layer and a crystalline silicon top layer. Related semiconductor structures are described.