Buffer Chamber for Uniform ALD Gas Injection
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Solution Overview
Problem
Conventional batch-type atomic layer deposition (ALD) apparatuses suffer from non-uniform supply of reaction gases due to insufficient pressure, leading to thickness variations in thin layers on semiconductor substrates, which cause processing defects and performance issues in semiconductor devices.
Innovation Solution
The method involves forming a metal precursor gas at higher than atmospheric pressure by discharging it into a buffer and controlling the pressure through a vaporizer, ensuring uniform injection into the processing chamber, and using a second source gas to convert the precursor layer into a metal layer, while maintaining a consistent purge gas flow to enhance uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If source gas pressure is increased to improve uniformity of thin layer deposition, then manufacturing precision is improved, but device complexity increases due to additional pressure control mechanisms
Solution Approach 1:
A buffer chamber is introduced as an intermediary component between the gas source and the deposition chamber. The buffer chamber receives source gas at a first pressure, accumulates it, and then supplies it at a controlled second pressure to the deposition chamber. This mediator enables pressure transformation and uniform gas supply without requiring complex real-time pressure control mechanisms throughout the entire system.
Solution Approach 2:
The system changes the pressure parameter of the source gas by accumulating it in the buffer chamber at a first pressure and then supplying it at a different, controlled second pressure. This parameter transformation allows optimization of both gas supply uniformity and deposition quality without maintaining high complexity throughout the system.
2Productivity
If vaporizer temperature is maintained constantly for efficient operation, then productivity is improved, but energy consumption increases due to continuous heating during idle periods
Solution Approach 1:
The buffer chamber performs preliminary accumulation of source gas during idle periods when the vaporizer is already heated and producing gas. By storing the gas in the buffer chamber during these periods, the system prepares for future deposition operations without requiring continuous high-energy operation of the vaporizer at full capacity, thus reducing overall energy consumption while maintaining productivity.
3Ease of manufacture
If source gas is supplied at low pressure due to high molecular weight materials, then ease of manufacture is improved, but manufacturing precision deteriorates due to non-uniform gas distribution
Solution Approach 1:
The buffer chamber serves as a mediator that decouples the relationship between source gas pressure and deposition quality. It receives gas at low pressure (making manufacturing easy) and supplies it at a controlled, optimized pressure (ensuring deposition precision). This intermediary allows the system to benefit from both low-pressure material handling and high-pressure uniform deposition without direct conflict.
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 significantly improves the uniformity of thin layer thickness across semiconductor substrates, reducing deviations and enhancing the performance of semiconductor devices by ensuring consistent gas injection and layer formation.
Implementation Method 1
a vaporizer for vaporizing liquid source materials
Implementation Method 2
a buffer for receiving a source gas from the vaporizer and increasing a pressure of the source gas to higher than atmospheric pressure
Implementation Method 3
a deposition process, such as a chemical vapor deposition (CVD) process, a physical vapor deposition (PVD) process and an atomic layer deposition (ALD) process
Data Source
AI summary
An apparatus and a method form a thin layer on each of multiple semiconductor substrates. A processing chamber of the apparatus includes a boat in which the semiconductor substrates are arranged in a vertical direction. A vaporizer vaporizes a liquid metal precursor into a metal precursor gas. A buffer receives a source gas from the vaporizer and increases a pressure of the source gas to higher than atmospheric pressure, the source gas including the metal precursor gas. A first supply pipe connects the buffer and the processing chamber, the first supply pipe including a first valve for controlling a mass flow rate of the source gas. A second supply pipe connects the vaporizer and a pump for creating a vacuum inside the processing chamber, the second supply pipe including a second valve for exhausting a dummy gas during an idling operation of the vaporizer.