Substrate Processing Apparatus Pulsed Ozone Supply for Film Uniformity
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Solution Overview
Problem
Conventional vertical substrate processing apparatuses face challenges in achieving uniform film thickness and composition distribution during oxide film formation, leading to variations in semiconductor device characteristics and reduced manufacturing yield due to uneven oxidation, particularly on the center part of wafers.
Innovation Solution
A substrate processing method involving alternating supply of source gas and ozone into a processing chamber, with ozone being reserved in a gas reservoir and supplied pulsed-fashion to ensure uniform coverage, while maintaining a controlled atmosphere to prevent mixing and optimize film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If continuous exhaust is maintained during oxide gas supply, then source gas and oxide gas can be removed efficiently, but processing time increases and productivity decreases
Solution Approach 1:
The patent applies periodic action by alternately stopping the exhaust operation during oxide gas supply cycles. The exhaust is stopped intermittently to allow oxide gas to accumulate and diffuse uniformly throughout the processing chamber, then restarted to remove excess gas. This periodic exhaust control reduces total processing time while maintaining film thickness uniformity across the substrate surface.
2Productivity
If ozone is supplied at high concentration, then oxidation reaction efficiency increases, but uniformity of film thickness distribution deteriorates due to premature reaction in chamber
Solution Approach 1:
The patent applies preliminary action by pre-cooling the ozone gas before it enters the processing chamber. The ozone is cooled to a lower temperature in advance, which suppresses premature oxidation reactions during gas transport and chamber filling. This allows high concentration ozone to be supplied efficiently while maintaining uniform film thickness distribution, as the reaction is controlled to occur primarily on the substrate surface rather than in the gas phase.
3Productivity
If source gas and oxide gas are supplied simultaneously, then processing cycle time is reduced, but film composition uniformity deteriorates due to gas mixing
Solution Approach 1:
The patent applies segmentation by dividing the film formation process into distinct sequential stages: source gas supply stage, exhaust stage, oxide gas supply stage, and exhaust stage. This segmented approach prevents mixing of source gas and oxide gas, ensuring uniform film composition. The alternating supply and removal cycles are optimized to minimize total processing time while maintaining composition uniformity through clear temporal separation of gas phases.
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 approach shortens processing time, improves film thickness uniformity, and enhances the manufacturing yield by ensuring consistent oxidation across the wafer surface, reducing waste and maintaining high productivity.
Implementation Method 1
the oxide gas jetted from each gas jet hole of the second gas supply nozzle 233b is flown horizontally on each wafer, which is then reacted with the base film formed on the wafer, to thereby form an oxide film on the wafer
Implementation Method 2
the source gas jetted from each gas jet hole of the first gas supply nozzle 233a is flown horizontally on each wafer, then is adsorbed on the surface of the wafer, to thereby form a base film on the wafer
Data Source
AI summary
There is provided a substrate processing method, comprising the steps of: supplying source gas into a processing chamber in which substrates are accommodated; removing the source gas and an intermediate body of the source gas remained in the processing chamber; supplying ozone into the processing chamber in a state of substantially stopping exhaust of an atmosphere in the processing chamber; and removing the ozone and the intermediate body of the ozone remained in the processing chamber; with these steps repeated multiple number of times, to thereby form an oxide film on the surface of the substrates by supplying the source gas and the ozone alternately so as not to be mixed with each other.