Sputtering Apparatus Non-Uniform Substrate Rotation
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Solution Overview
Problem
Conventional sputtering methods, such as oblique incidence and rotation, result in non-uniform film thickness on substrates with relief structures like mesa or trench configurations due to varying distances between the target and substrate surfaces, leading to inconsistencies in film deposition on side surfaces.
Innovation Solution
A sputtering apparatus with a substrate holder and position detecting means to adjust rotation speed and stop time, and power control for the cathode unit, ensuring uniform film thickness by optimizing the deposition process based on the rotational position of the substrate relative to the target.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oblique incidence sputtering with substrate rotation is used, then coating properties on bottom surface and inner wall surface are improved, but film thickness distribution uniformity deteriorates
Solution Approach 1:
The patent applies dynamics by making the substrate rotation non-uniform - specifically rotating the substrate at different speeds during different phases of the deposition cycle. The substrate rotates slowly during sputtering deposition and faster during repositioning, allowing optimization of both coating quality and thickness uniformity through time-varying motion control
Solution Approach 2:
The patent implements periodic action through cyclic substrate rotation that alternates between slow rotation during deposition phases and fast rotation during repositioning phases. This periodic variation in rotation speed ensures uniform film thickness accumulation while maintaining good coating properties on complex surface geometries
2Reliability
If mask is provided to control incident sputter particles, then coating properties are improved, but particle generation from film peeling increases
Solution Approach 1:
The patent extracts and eliminates the mask component from the system entirely. Instead of using a physical mask to control sputter particle incidence, the invention uses controlled substrate rotation to achieve selective deposition, thereby avoiding particle generation from mask film peeling
Solution Approach 2:
The patent introduces substrate rotation as an intermediary mechanism to control deposition patterns. Rather than using a mask to physically block particles, the rotating substrate dynamically positions different areas to receive sputter particles, achieving mask-like control without the harmful effects
3Reliability
If remote low-pressure sputtering or bias sputtering is used, then bottom surface and inner wall surface coating is achieved, but film thickness uniformity deteriorates
Solution Approach 1:
The patent applies dynamics by implementing time-varying substrate rotation speeds during the deposition process. The substrate rotates slowly during actual sputtering to allow uniform particle accumulation, then rotates faster to reposition for the next deposition cycle, achieving both good coating and uniform thickness
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 effectively reduces film thickness variations between opposing surfaces of relief structures by controlling the substrate's rotation speed and power supply, achieving more uniform film deposition across the substrate.
Implementation Method 1
a cathode unit configured to sputter a target arranged at a position diagonally opposite to the substrate holder
Implementation Method 2
cathode unit configured to sputter at least one sputtering target arranged at a position diagonally opposite to the substrate holder by plasma generated by supplying power to the cathode unit
Data Source
AI summary
A sputtering apparatus according to one embodiment of the present invention includes a substrate holder, a cathode unit arranged at a position diagonally opposite to the substrate holder, a position sensor for detecting a rotational position of the substrate, and a holder rotation controller for adjusting a rotation speed of the substrate according to the detected rotational position. The holder rotation controller controls the rotation speed so that the rotation speed of the substrate when the cathode unit is located on a side in a first direction as an extending direction of a process target surface of the relief structure is lower than the rotation speed of the substrate when the cathode unit is located on a side in a second direction which is perpendicular to the first direction along the rotation of the substrate.