Substrate Processing Apparatus Phosphorus Diffusion Region Control
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Solution Overview
Problem
Existing substrate processing methods face challenges in effectively removing residual phosphorus from silicon nitride films after phosphoric acid treatment, leading to substrate deterioration due to residual impurities and phosphorus diffusion.
Innovation Solution
A substrate processing method and apparatus that involves sequential processing with a phosphoric acid liquid, a rinsing liquid, and a chemical liquid containing ammonia, where the chemical liquid is used to remove a portion of the film thickness in the phosphorus diffusion region, forming a protective film to inhibit substrate deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If phosphoric acid liquid is used to process the substrate, then the silicon nitride film is effectively etched, but residual phosphorus remains in the phosphorus diffusion region causing substrate deterioration
Solution Approach 1:
The etching process is segmented into multiple sequential steps: first etching with phosphoric acid liquid to remove the silicon nitride film, then treating with a chemical liquid containing ammonia to remove residual phosphorus from the phosphorus diffusion region. This segmentation allows each step to address a specific aspect of the problem without compromising the other.
Solution Approach 2:
The residual phosphorus, which is harmful to substrate quality, is converted into a removable byproduct through treatment with the chemical liquid containing ammonia. The ammonia reacts with the phosphorus to form soluble compounds that can be easily washed away, transforming the harmful residual phosphorus into a beneficial removable substance.
2Device complexity
If residual phosphorus is not removed, then the processing is simpler, but impurity growth occurs and substrate quality deteriorates
Solution Approach 1:
The processing is divided into distinct segments: the primary etching step followed by a secondary treatment step with chemical liquid. This segmentation adds a relatively simple additional step that specifically targets phosphorus removal without requiring complete process redesign, thus increasing reliability with minimal complexity addition.
Solution Approach 2:
The chemical liquid containing ammonia acts as an intermediary substance that mediates between the phosphoric acid etching process and the final substrate quality. It serves as a bridge that removes the harmful intermediate product (residual phosphorus) without affecting the previously achieved etching results.
3Quantity of substance
If the film thickness in the phosphorus diffusion region is not reduced, then residual phosphorus accumulates, but reducing it forms a protective film that prevents further deterioration
Solution Approach 1:
The chemical liquid containing ammonia changes the physical and chemical parameters of the phosphorus diffusion region by reacting with residual phosphorus to form a protective film. This parameter change transforms the harmful residual phosphorus into a stable protective layer, simultaneously reducing the quantity of free phosphorus and creating a beneficial protective barrier.
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
The method effectively reduces substrate deterioration by removing residual phosphorus and forming a protective film, thereby preventing impurity growth and maintaining substrate quality.
Implementation Method 1
processing the substrate with a phosphoric acid liquid
Implementation Method 2
processing the substrate with a chemical liquid containing ammonia... to remove a portion of thickness of a film in a depth direction of a phosphorus diffusion region
Implementation Method 3
forming a protective film to inhibit substrate deterioration
Data Source
AI summary
Provided is a substrate processing method for processing a substrate. The substrate processing method includes a step of processing the substrate with a phosphoric acid liquid, a step of processing the substrate with a rinsing liquid, and a step of processing the substrate with a chemical liquid containing ammonia. After the substrate is processed with the rinsing liquid, the step of processing the substrate with a chemical liquid removes a portion of thickness of a film in a depth direction of a phosphorus diffusion region from the phosphorus diffusion region formed in the substrate when the substrate is processed with the phosphoric acid liquid.