Semiconductor Film Deposition in Deep Concaves for Better Step Coverage
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Solution Overview
Problem
In semiconductor device manufacturing, as devices miniaturize, the aspect ratio of concave structures on substrates increases, leading to inadequate step coverage performance during film deposition, where excessive gas supply to the upper portion of the device hampers improved coverage to the lower portions.
Innovation Solution
A technique involving a cycle of supplying a source gas to collide with the inner wall of concave structures, decomposing it to form an intermediate substance that reacts with a reactive gas, enhancing film deposition on the substrate's concave surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the source gas is supplied to sufficiently reach the lower portion of the concave structure, then the step coverage performance is improved, but the upper portion of the device receives excessive process gas which prevents further improvement
Solution Approach 1:
The gas supply process is segmented into two distinct stages: first supplying source gas to decompose and form intermediate substance on the inner wall, then supplying reactive gas to complete the film formation. This segmentation allows precise control of gas distribution at different locations and times, enabling improved step coverage without excessive gas supply to the upper portion.
Solution Approach 2:
The source gas is supplied first to perform preliminary decomposition and form intermediate substance on the inner wall of the concave structure before the reactive gas is introduced. This preliminary action ensures that the lower portion receives adequate precursor material while controlling the overall gas supply timing and distribution.
2Area of moving object
If the aspect ratio of concave structure increases due to device miniaturization, then the device density is improved, but the gas supply to the lower portion becomes insufficient leading to poor step coverage
Solution Approach 1:
An intermediate substance is formed on the inner wall of the concave structure through decomposition of source gas. This intermediate substance acts as a mediator that facilitates subsequent reaction with reactive gas, enabling effective film formation in deep concave structures with high aspect ratios where direct gas supply would be insufficient.
Solution Approach 2:
The chemical state of the gas is changed through decomposition to form an intermediate substance, which then reacts with the reactive gas. This parameter change from molecular source gas to intermediate substance enables the gas to adhere to and react within deep concave structures, improving step coverage for high aspect ratio features.
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 improves step coverage performance by ensuring sufficient gas supply to the lower portions of concave structures while minimizing excess gas on the upper portions, thereby enhancing film deposition efficiency.
Implementation Method 1
by colliding the source gas with an inner wall of the concave structure, the source gas is decomposed to generate an intermediate substance and the intermediate substance adheres to the inner wall of the concave structure
Implementation Method 2
the intermediate substance adheres to the inner wall of the concave structure
Implementation Method 3
the intermediate substance adhered to the inner wall of the concave structure reacts with the reactive gas
Data Source
AI summary
According to the present disclosure, the step coverage performance of the film can be improved on the substrate. According to one embodiment of the present disclosure, there is provided a technique that includes: forming a film on a substrate provided with a concave structure on a surface thereof by performing a cycle a predetermined number of times, wherein the cycle includes: (a) supplying a source gas to the substrate from a side of the substrate; and (b) supplying a reactive gas to the substrate, and wherein, in (a), by colliding the source gas with an inner wall of the concave structure, the source gas is decomposed to generate an intermediate substance and the intermediate substance adheres to the inner wall of the concave structure, and wherein, in (b), the intermediate substance adhered to the inner wall of the concave structure reacts with the reactive gas.