Substrate Oxidation Uniformity via Alternating Gas Flow
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Solution Overview
Problem
The existing semiconductor manufacturing processes face challenges in achieving uniform film thickness on substrates due to variations in oxidation rates across the substrate surface during the oxidization and film formation processes.
Innovation Solution
A technique involving a substrate processing apparatus that alternates between oxidizing the substrate surface with increasing and decreasing oxidation amounts along the gas flow direction by supplying oxygen-containing and hydrogen-containing gases, followed by forming a film on the initial oxide layer using a precursor gas, to improve film thickness uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single oxidation process is performed with uniform gas flow, then the process is simple and fast, but the film thickness uniformity across the substrate deteriorates
Solution Approach 1:
The oxidation process is divided into multiple sequential stages with different gas flow patterns. The first oxidation stage uses a gas flow pattern that creates higher oxidation rate at the center, while the second oxidation stage uses a reversed gas flow pattern that creates higher oxidation rate at the edges. This segmentation allows each stage to address specific thickness uniformity issues, resolving the contradiction between precision and complexity.
Solution Approach 2:
The patent employs periodic alternation between different oxidation conditions. By switching between two opposite gas flow patterns in sequential oxidation stages, the process creates a periodic action that compensates for thickness variations. This periodic reversal of oxidation rate distribution improves film thickness uniformity while maintaining a relatively simple overall process structure.
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 enhances the inter-wafer thickness uniformity of the initial oxide layer and subsequently the film formed on the substrate, improving productivity and maintaining film quality with controlled oxidation processes.
Implementation Method 1
oxidizing the surface of the substrate under a condition that an oxidation amount of the substrate increases from an upstream side to a downstream side of a gas flow by supplying an oxygen-containing gas and a hydrogen-containing gas to the substrate
Implementation Method 2
forming a film on the initial oxide layer by supplying a precursor gas to the substrate
Data Source
AI summary
There is provided a technique that includes: forming an initial oxide layer on a surface of a substrate by performing a set m times (where m is an integer equal to or greater than 1), the set including non-simultaneously performing: (a) oxidizing the surface of the substrate under a condition that an oxidation amount of the substrate increases from an upstream side to a downstream side of a gas flow by supplying an oxygen-containing gas and a hydrogen-containing gas to the substrate; and (b) oxidizing the surface of the substrate under a condition that the oxidation amount of the substrate decreases from the upstream side to the downstream side of the gas flow by supplying the oxygen-containing gas and the hydrogen-containing gas to the substrate; and forming a film on the initial oxide layer by supplying a precursor gas to the substrate.