Crystalline Alloy Sputtering Target Thermal Stability
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Solution Overview
Problem
Amorphous targets used in sputtering processes are prone to thermal instability, leading to localized crystallization and increased brittleness, which can result in target fracture during the sputtering process, disrupting production stability and thin film uniformity.
Innovation Solution
A crystalline alloy with glass-forming ability, composed of three or more elements including 5-20 at% aluminum, 15-40 at% of copper or nickel, and the remainder zirconium, with controlled grain sizes between 0.1 μm to 5 μm, is used to create a stable sputtering target by heat-treating amorphous or nanocrystalline alloys within specific temperature ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an amorphous target is used in sputtering process, then the target can form amorphous thin films, but the target structure changes due to thermal instability and localized crystallization occurs
Solution Approach 1:
The patent applies phase transition by transforming the target material from amorphous phase to nanocrystalline phase through controlled heat treatment. The amorphous alloy target is heated to a specific temperature range (0.5-0.8 times the melting point) to induce crystallization, forming a nanocrystalline structure that maintains glass-forming ability while providing thermal stability during sputtering process
Solution Approach 2:
The patent changes the structural parameters of the alloy by controlling grain size to 100 nm or less through heat treatment temperature and time optimization. This parameter control transforms the material from amorphous to nanocrystalline state, achieving both thermal stability and glass-forming ability simultaneously
2Productivity
If the target temperature increases during sputtering, then the sputtering process can proceed, but localized crystallization occurs on the target surface
Solution Approach 1:
The patent applies preliminary action by pre-heating the amorphous alloy target to induce crystallization before the actual sputtering process. This preliminary heat treatment transforms the target into a nanocrystalline structure that is thermally stable, preventing any further crystallization during subsequent sputtering operations even when target temperature increases
3Reliability
If the alloy grain size is reduced to increase thermal stability, then the target becomes more stable, but the manufacturing precision becomes more difficult to control
Solution Approach 1:
The patent precisely controls grain size parameter by optimizing heat treatment temperature and time. By maintaining grain size at 100 nm or less through controlled annealing, the patent achieves nanocrystalline structure that provides thermal stability while ensuring uniform microstructure and composition in the resulting thin 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 crystalline alloy significantly enhances thermal and mechanical stability, preventing target fracture and ensuring uniform microstructure and composition of the thin film, thereby stabilizing the sputtering process and maintaining target integrity.
Implementation Method 1
heating an amorphous alloy or a nanocrystalline alloy having glass-forming ability... in a temperature range of a crystallization initiation temperature of the amorphous alloy or the nanocrystalline alloy or higher but lower than a melting temperature thereof
Implementation Method 2
controlling an average grain size of the crystalline alloy to 5 μm or less by heating
Data Source
AI summary
Provided are a crystalline alloy having significantly better thermal stability than an amorphous alloy as well as glass-forming ability, and a method of manufacturing the crystalline alloy. The present invention also provides an alloy sputtering target that is manufactured by using the crystalline alloy, and a method of manufacturing the alloy target. According to an aspect of the present invention, provided is a crystalline alloy having glass-forming ability which is formed of three or more elements having glass-forming ability, wherein the average grain size of the alloy is in a range of 0.1 μm to 5 μm and the alloy includes 5 at % to 20 at % of aluminum (Al), 15 at % to 40 at % of any one or more selected from copper (Cu) and nickel (Ni), and the remainder being zirconium (Zr).