Reciprocating Magnet Sputtering for Uniform ITO Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sputtering apparatuses result in non-uniform sheet resistance distribution of ITO films on substrates during deposition, leading to variations in film quality and resistance values across the substrate transfer direction.
Innovation Solution
A substrate transfer type sputtering apparatus with two magnetron sputtering units, where the magnetron units include a reciprocating magnet, an electrically insulated floating target shield, and cathode shields with specific configurations to ensure uniform plasma distribution and deposition, with the first cathode shield on the upstream side being electrically insulated and the second cathode shield grounded, facilitating uniform ITO film deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the magnet movement speed is increased to achieve uniform film thickness distribution, then the film uniformity is improved, but the mechanical durability of the magnet movement unit deteriorates and nodules are generated on the target surface
Solution Approach 1:
The magnet is designed to reciprocate (move back and forth) in the substrate transfer direction rather than moving continuously in one direction. This dynamic reciprocating motion allows the magnet to cover the entire target surface area uniformly, achieving even film thickness distribution while operating at lower speeds that preserve mechanical durability and prevent nodule generation on the target surface.
2Reliability
If the magnet movement speed is decreased to improve mechanical durability, then the mechanical durability is improved, but the film thickness distribution uniformity deteriorates
Solution Approach 1:
The reciprocating motion of the magnet in the substrate transfer direction ensures that even at lower speeds, the magnet can systematically cover the entire target surface. The back-and-forth movement pattern maintains uniform plasma distribution and film deposition across the substrate, resolving the contradiction between low speed operation and film uniformity.
3Quantity of substance
If conventional sputtering deposition is performed, then ITO film is deposited on substrate, but sheet resistance value changes periodically in substrate transfer direction causing non-uniform distribution
Solution Approach 1:
The magnet reciprocates in the substrate transfer direction to ensure uniform plasma distribution across the entire target surface. This dynamic motion prevents the periodic variation in sheet resistance values that occurs with conventional stationary or unidirectionally moving magnets, achieving uniform ITO film properties throughout the substrate.
Solution Approach 2:
The cathode shield structure is designed with different electrical connection configurations (first cathode shield electrically connected, second cathode shield not electrically connected) to locally control plasma distribution. This addresses the sheet resistance uniformity issue by optimizing the local plasma environment in different regions of the deposition chamber.
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 apparatus achieves uniform sheet resistance and low resistance ITO films across the substrate transfer direction, improving film quality and reducing mechanical stress on the magnet movement unit, suitable for high-functional device substrates.
Implementation Method 1
a film deposit apparatus for depositing an ITO thin film on a substrate by sputtering
Implementation Method 2
a magnet (magnetic circuit) of respective magnetron sputtering units
Data Source
AI summary
A sputtering deposit apparatus capable of depositing a thin film having uniform sheet resistance value is provided. The sputtering deposit apparatus is arranged with at least two magnetron sputtering units within a film deposit chamber. On the upstream side in the substrate transfer direction 43 of the target shield 55 provided on the magnetron sputtering unit disposed on the most upstream side in the substrate transfer direction, of at least the two magnetron sputtering units, there is disposed the first cathode shield 62 which is electrically insulated.