Deposition Device Gas Flow Control for Film Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional deposition techniques face challenges in achieving high in-plane uniformity of film thickness and deposition rate, especially when using organometallic compounds like Ru3(CO)12, due to issues such as film thickness variations and material recovery difficulties, particularly in semiconductor wafer processing.
Innovation Solution
A deposition device design featuring a processing container with a gas introduction mechanism that directs source gas beyond the wafer's peripheral end, an internal partition wall with a radially inward orifice forming member, and a purge gas supply mechanism, maintaining temperatures below the source gas's decomposition point to prevent unnecessary film deposition and enhance material recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If source gas is supplied to the central portion of the semiconductor wafer, then film deposition is achieved, but film thickness of the central portion increases excessively and in-plane uniformity deteriorates
Solution Approach 1:
The gas introduction mechanism extracts the source gas supply from the central portion of the wafer and redirects it to the peripheral region. The baffle plate blocks direct downward flow to the center, while the gas discharge ports positioned at the peripheral edge supply source gas only to the peripheral region, preventing excessive central film thickness while maintaining deposition efficiency.
Solution Approach 2:
Instead of supplying source gas from the center outward, the system inverts the approach by supplying source gas from the peripheral edge inward. The gas discharge ports are positioned at the peripheral edge of the baffle plate, causing source gas to be introduced first at the periphery and then diffuse toward the center, achieving uniform deposition without central accumulation.
2Manufacturing precision
If most source gas is exhausted from the gas outlet, then central film thickness is controlled, but deposition rate becomes insufficient
Solution Approach 1:
The system applies local quality by creating different gas flow characteristics in different regions. The peripheral region receives high浓度的 source gas from the discharge ports for efficient deposition, while the central region receives diffused gas at lower concentration to prevent excessive thickness. The baffle plate structure creates localized flow patterns that optimize deposition in each region.
Solution Approach 2:
The baffle plate acts as an intermediary element that mediates between the source gas supply and the wafer surface. It redirects the gas flow, creates diffusion paths, and controls the distribution pattern. The internal partition wall also serves as an intermediary to guide gas flow and enhance mixing, ensuring both uniformity and adequate deposition rate.
3Productivity
If mounting platform is heated to high temperature, then film deposition is promoted, but source gas decomposes on peripheral edges causing unnecessary film deposition
Solution Approach 1:
The system segments the heating function by separating the wafer heating from the peripheral region heating. The mounting platform heats only the wafer area, while the baffle plate and internal partition wall remain at lower temperatures. This segmentation prevents source gas decomposition on peripheral components while maintaining efficient deposition on the wafer.
Solution Approach 2:
The system converts the potential harm of source gas decomposition into a benefit by using the baffle plate's lower temperature region as a decomposition suppression zone. The source gas that would otherwise decompose on hot peripheral surfaces is instead directed through the cooler baffle plate region, where it decomposes in a controlled manner that promotes uniform deposition rather than forming unwanted films.
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 solution achieves a higher deposition rate while maintaining high in-plane uniformity of film thickness and effectively recovers expensive organometallic compounds, preventing film deposition on peripheral edges and improving material recovery rates.
Implementation Method 1
The metal carbonyl raw material can be easily pyrolyzed at a relatively low temperature to form a metal film and CO gas
Implementation Method 2
CO gas having a decomposition suppressing function is utilized as a carrier gas
Implementation Method 3
a portion of the source gas is diffused to flow toward a central portion of the processing space
Data Source
AI summary
The disclosed deposition device for forming a thin film using a starter gas comprising an organic metal compound is provided with: a processing container 22; a mounting platform 28 which has a heater 34 for heating the workpiece W; a gas introduction mechanism 80 which introduces the starter gas toward the area more exterior than the outer peripheral end of the workpiece W on the mounting platform 28; an internal partition wall 90 which is disposed such that the lower end of said processing space contacts the mounting platform 28 to form gas outlets 92 between the lower portion of the space and the edges of the mounting platform 28; and a orifice forming member 96 which extends radially inward toward the mounting platform 28 and forms an orifice 98 communicating with the gas outlet 92.