Film Formation Time Setting for Silicon Substrate Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing film formation methods face challenges in achieving uniformity of silicon-containing film thickness across multiple substrates due to factors like raw material gas distribution and nozzle positioning, leading to inconsistencies in film formation time and quality.
Innovation Solution
A film formation time setting method that involves a provisional film forming process with multiple cycles, measuring film thickness at different stages, and adjusting the film formation time to achieve optimal inter-plane uniformity by comparing film thickness measurements at various cycle times to specify the optimal film formation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the film formation time is set based on cycle time and number of cycles, then the film thickness can be controlled, but the inter-plane uniformity of film thickness across substrates deteriorates due to gas distribution variations and nozzle positioning effects
Solution Approach 1:
The invention performs preliminary film formation for a predetermined time before the main film formation process. This preliminary action allows the system to reach a stable state where gas distribution and nozzle positioning effects are minimized, ensuring that subsequent film formation occurs under optimal uniformity conditions. The preliminary step compensates for initial transient effects that would otherwise cause non-uniform film thickness across substrates.
Solution Approach 2:
The film formation process is divided into two distinct segments: a preliminary film formation stage and a main film formation stage. This segmentation allows each stage to serve a specific purpose - the preliminary stage establishes stable gas flow patterns and uniform deposition conditions, while the main stage achieves the target film thickness. This separation resolves the contradiction by ensuring uniformity is established before thickness accumulation becomes the primary concern.
2Productivity
If the raw material gas supply is increased to accelerate film formation, then the productivity improves, but the inter-plane uniformity deteriorates due to excessive gas spreading to upstream substrates
Solution Approach 1:
The preliminary film formation stage establishes stable gas flow patterns and pressure distributions before the main formation process. This pre-conditioning allows the main stage to operate at higher gas supply rates for improved productivity while maintaining uniformity, as the stable baseline prevents excessive gas spreading to upstream substrates.
Solution Approach 2:
The process uses periodic gas supply cycles with distinct phases - a preliminary phase that establishes stable flow patterns, followed by main formation phases that can operate at higher intensities. This periodic structure with alternating intensity levels allows the system to achieve high overall productivity while maintaining uniformity during critical deposition periods.
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 ensures improved inter-plane uniformity of silicon-containing films by identifying the optimal film formation time, reducing variations and enhancing film quality across all substrates.
Implementation Method 1
a silicon-containing film is formed on each of the substrates placed on the rotary table as the substrates sequentially pass through the above areas of the processing chamber
Data Source
AI summary
A film formation time setting method to be implemented when forming silicon-containing films on a plurality of substrates arranged on a rotary table includes a film thickness measuring step of performing a provisional film forming process for a provisional film formation time T×N, provisionally set up based on a cycle time T and a number of cycles N, measuring film thicknesses dN-1 of the silicon-containing films formed on the substrates at an end time of the (N-1)th cycle, measuring film thicknesses dN-1˜N of the silicon-containing films at an intermediate time between the (N-1)th cycle and the Nth cycle, and measuring film thicknesses dN of the silicon-containing films at an end time of the Nth cycle; and a film formation time specifying step of comparing the inter-plane uniformities of the silicon-containing films at the respective times to specify and set a film formation time for achieving an optimal inter-plane uniformity.