High-Purity Copper Sputtering Target Inclusion Control
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Solution Overview
Problem
Conventional high-purity copper or copper alloy sputtering targets contain trace amounts of nonmetal inclusions, particularly carbon system inclusions, which lead to particle generation during sputtering, causing defects in semiconductor devices, especially as device integration and miniaturization advance, and existing technologies fail to adequately address these inclusions.
Innovation Solution
A high-purity copper or copper alloy sputtering target with a purity of 6N or higher, where the content of P, S, O, and C is 1ppm or less, and the number of nonmetal inclusions with a particle size of 0.5µm to 20µm is reduced to 30,000 inclusions/g or less, using a cold crucible melting or vacuum arc remelting process, effectively minimizing carbon system inclusions to 15,000 inclusions/g or less and ensuring they comprise 50% or less of nonmetal inclusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sputtering targets with trace nonmetal inclusions are used, then manufacturing cost and process simplicity are maintained, but particle generation occurs during sputtering causing semiconductor device defects
Solution Approach 1:
The patent applies preliminary action by reducing nonmetal inclusions to 30,000 inclusions/g or less (preferably 15,000 inclusions/g or less) in the copper target before the sputtering process begins. This pre-treatment ensures that particle generation during sputtering is minimized, thereby preventing semiconductor device defects without requiring complex in-situ control mechanisms during manufacturing.
Solution Approach 2:
The patent changes the critical parameter of nonmetal inclusion density from conventional levels (not specified) to 30,000 inclusions/g or less, with a preference for 15,000 inclusions/g or less. This parameter change fundamentally alters the target's performance characteristics, enabling high-quality sputtering films while maintaining manufacturing feasibility through controlled impurity levels.
2Object-generated harmful factors
If trace nonmetal inclusions are eliminated completely, then particle generation is prevented, but manufacturing cost and process complexity increase significantly
Solution Approach 1:
The patent applies partial action by reducing nonmetal inclusions to 30,000 inclusions/g or less (preferably 15,000 inclusions/g or less) rather than achieving complete elimination. This partial reduction is sufficient to prevent problematic particle generation during sputtering while avoiding the exponentially increasing costs and complexities associated with achieving absolute zero inclusions.
Solution Approach 2:
The patent converts the previously harmful nonmetal inclusions into a controlled parameter by establishing specific inclusion density thresholds (30,000 inclusions/g or less, preferably 15,000 inclusions/g or less). This transformation allows the manufacturing process to work with rather than against the inevitable presence of trace inclusions, maintaining ease of manufacture while eliminating harmful particle generation effects.
3Manufacturing precision
If high-purity copper with reduced nonmetal inclusions is used, then sputtered film quality improves, but target manufacturing complexity increases
Solution Approach 1:
The patent changes the nonmetal inclusion density parameter to 30,000 inclusions/g or less (preferably 15,000 inclusions/g or less), which directly improves sputtered film quality by preventing particle generation. This parameter change is achieved through controlled manufacturing processes that balance purity requirements with manufacturing feasibility.
Solution Approach 2:
The patent implements feedback control by establishing measurable inclusion density thresholds (30,000 inclusions/g or less, preferably 15,000 inclusions/g or less) that can be monitored and controlled during target manufacturing. This feedback mechanism ensures consistent sputtered film quality while maintaining manageable manufacturing complexity through quantifiable control criteria.
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
This approach significantly reduces the percentage of defective semiconductor device wirings by inhibiting particle generation during sputtering, resulting in a superior sputtered film quality with fewer carbon or carbide particles, suitable for advanced semiconductor technology.
Implementation Method 1
the raw material is melted through a cold crucible melting process or a vacuum arc remelting process
Implementation Method 2
The sputtering method is to form a film on a substrate by utilizing the phenomenon where atoms configuring the target are discharged into space and accumulated on the opposing substrate based on the momentum exchange that occurs when the accelerated charged particles collide with the target surface
Data Source
AI summary
Provided is a high-purity copper or high-purity copper alloy sputtering target of which the purity is 6N or higher and in which the content of the respective components of P, S, O and C is 1 ppm or less, wherein the number of nonmetal inclusions having a particle size of 0.5µm or more and 20µm or less is 30,000 inclusions/g or less. As a result of using high-purity copper or high-purity copper alloy from which harmful inclusions of P, S, C and O system have been reduced as the raw material and controlling the existence form of nonmetal inclusions, the present invention addresses a reduction in the percent defect of wirings of semiconductor device formed by sputtering a high-purity copper target so as to ensure favorable repeatability.