Processing Chamber Cleaning with Staged HF-Ammonia Etching
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Solution Overview
Problem
Existing methods for removing deposits from processing chambers are inefficient in completely etching all areas, particularly where temperature variations occur, leading to residual film residues.
Innovation Solution
A two-step cleaning process involving a first cleaning process with hydrogen fluoride gas at a lower temperature to quickly remove deposits, followed by a second cleaning process with a mixture of hydrogen fluoride and ammonia gas at a higher temperature to ensure complete etching, utilizing chemical oxide removal (COR) to sublimate ammonium silicofluoride and remove residual deposits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single cleaning process with hydrogen fluoride gas is used, then the cleaning process is simple, but deposits in areas with temperature variations are not completely removed
Solution Approach 1:
The cleaning process is divided into two distinct steps: first using hydrogen fluoride gas at a lower temperature to quickly remove most deposits, then using a mixture of hydrogen fluoride and ammonia gases at a higher temperature to completely remove residual deposits. This segmentation allows each step to optimize for its specific function, resolving the contradiction between process simplicity and removal completeness.
Solution Approach 2:
The invention changes multiple parameters between the two cleaning steps: temperature is increased from the first to second step, and gas composition is changed by adding ammonia to the hydrogen fluoride. These parameter changes enable the process to achieve both quick initial removal and complete residual removal, addressing the contradiction between simplicity and completeness.
2Manufacturing precision
If a two-step cleaning process with temperature adjustment and gas mixture is used, then complete deposit removal is achieved, but the cleaning process becomes more complex
Solution Approach 1:
By segmenting the cleaning process into two distinct steps with clearly defined functions, the complexity is organized and manageable. The first step handles bulk removal while the second step handles residual removal, making the overall complex process systematic and controllable rather than chaotic.
Solution Approach 2:
The two cleaning steps are performed in continuous sequence without interruption, with the second step immediately following the first. This continuity ensures that the useful action of deposit removal is maintained throughout, and the transition between steps is smooth, reducing operational complexity despite the multi-step nature of the process.
3Speed
If hydrogen fluoride gas is supplied at higher temperature, then etching speed increases, but film residues remain in certain areas
Solution Approach 1:
The first cleaning step using hydrogen fluoride gas performs a preliminary removal of the bulk of deposits, reducing the overall deposit load before the second step. This preliminary action allows the second step to focus on removing residual deposits in temperature-sensitive areas, achieving both speed and completeness.
Solution Approach 2:
The second cleaning step uses a mixture of hydrogen fluoride and ammonia gases at higher temperature specifically targeted at removing residual deposits. The ammonia component provides local chemical action that complements the hydrogen fluoride, creating a localized effect that addresses film residues in areas where temperature variations prevent complete removal by the first step alone.
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 removes all deposits from the processing chamber, reducing residual film residues and ensuring thorough cleaning for subsequent film deposition processes.
Implementation Method 1
supplying a first gas including a hydrogen fluoride gas into the processing chamber in which the temperature is adjusted to the first temperature
Implementation Method 2
supplying a second gas including the hydrogen fluoride gas and an ammonia gas into the processing chamber in which the temperature is adjusted to the second temperature
Implementation Method 3
utilizing chemical oxide removal (COR) to sublimate ammonium silicofluoride and remove residual deposits
Implementation Method 4
adjusting the temperature in the processing chamber to a second temperature that is higher than the first temperature
Data Source
AI summary
A cleaning method for removing a deposit in a processing chamber is provided. The cleaning method includes adjusting a temperature in the processing chamber to a first temperature; supplying a first gas including a hydrogen fluoride gas into the processing chamber in which the temperature is adjusted to the first temperature; adjusting the temperature in the processing chamber to a second temperature that is higher than the first temperature; and supplying a second gas including the hydrogen fluoride gas and an ammonia gas into the processing chamber in which the temperature is adjusted to the second temperature.