Sputtering target and magnetic film
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Solution Overview
Problem
Existing sputtering targets for magnetic recording media face issues with unstable discharge during film formation, leading to arcing and particle generation, which cannot be adequately addressed by previous refinement techniques, and the inclusion of Mn may not be preferable in all applications.
Innovation Solution
A sputtering target composition with 0.001 mol % to 0.5 mol % Bi, 45 mol % or less of Cr, 45 mol % or less of Pt, and 60 mol % or less of Ru, along with 1 mol % to 35 mol % of at least one metal oxide, balances Co and inevitable impurities, stabilizing discharge and reducing arcing by lowering the work function and enhancing electron emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If oxide particles are dispersed in Co-Cr-Pt metal phases for sputtering target, then film formation quality is improved, but arcing occurs during discharge causing particle generation
Solution Approach 1:
The invention changes the chemical composition parameters of the sputtering target by adding specific elements (Ta, W, Mo, or Hf) to modify the electronic structure and work function of the metal phase, thereby stabilizing discharge and reducing arcing while maintaining film formation quality
Solution Approach 2:
The invention creates a composite sputtering target material consisting of metal phases containing Co, Cr, Pt and specific amounts of Ta/W/Mo/Hf (0.01-5 at%), combined with oxide particles, forming a multi-component system that achieves both stable discharge and high-quality film formation
2Reliability
If discharge stability is improved by adding elements with lower work function, then arcing is reduced, but handling and maintenance become more difficult
Solution Approach 1:
Instead of using elements with very low work functions that are difficult to handle, the invention optimizes the content of Ta/W/Mo/Hf within a specific range (0.01-5 at%) to achieve sufficient discharge stability while maintaining ease of handling and manufacturing
Solution Approach 2:
The invention applies the low-work-function element strategy locally by adding small, controlled amounts of Ta/W/Mo/Hf specifically to the metal phase, rather than using elements throughout the entire target, thereby achieving discharge stability with minimal impact on handling
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 introduction of Bi in the sputtering target effectively stabilizes discharge, reduces arcing, and suppresses particle generation, even at lower electron densities and gas pressures, while being easier to handle and maintain than other metals with lower work functions.
Implementation Method 1
stabilizing discharge and reducing arcing by lowering the work function and enhancing electron emission
Implementation Method 2
stabilizing discharge and reducing arcing by lowering the work function and enhancing electron emission
Implementation Method 3
stabilizing discharge and reducing arcing by lowering the work function and enhancing electron emission
Data Source
AI summary
Provided is a sputtering target, comprising: from 0.001 mol % to 0.5 mol % of Bi; from 45 mol % or less of Cr; 45 mol % or less of Pt; 60 mol % or less of Ru; and a total of 1 mol % to 35 mol % of at least one metal oxide, the balance being Co and inevitable impurities.