Electroless Plating Rectification Mechanism for Wafer Film Homogeneity
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Solution Overview
Problem
Existing electroless plating methods for semiconductor wafers struggle to achieve high homogeneity in Ni film thickness and adhesion, leading to manufacturing challenges such as increased costs and reduced productivity, especially when dealing with thin wafers and multi-wafer processing.
Innovation Solution
A semiconductor-manufacturing apparatus featuring a rectification mechanism with through-holes and a driver that shakes the carrier in a controlled manner to maintain a constant positional relationship between wafers and the rectification plate, enhancing the flow and diffusion of plating solutions for uniform Ni film deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electroless plating is used to form Ni film, then manufacturing cost is reduced and patterning is facilitated, but film thickness homogeneity is insufficient
Solution Approach 1:
The patent introduces a shaking mechanism that dynamically moves the carrier holding multiple wafers during electroless plating. This dynamic motion prevents stagnant zones in the plating solution and ensures uniform distribution of plating chemicals across all wafer surfaces, achieving homogeneous film thickness while maintaining the cost advantages of electroless plating
Solution Approach 2:
The patent employs fluid dynamics by circulating and agitating the plating solution through hydraulic motion (shaking the carrier). This ensures continuous fresh plating solution contact with all wafer surfaces, preventing depletion zones and achieving uniform Ni film deposition across multiple wafers simultaneously
2Productivity
If multiple wafers are processed simultaneously, then productivity is enhanced, but film thickness homogeneity becomes difficult to control
Solution Approach 1:
The shaking mechanism dynamically redistributes the plating solution around all wafers during processing, ensuring that each wafer receives equivalent exposure to plating chemicals despite being processed simultaneously in bulk. This maintains uniform film thickness across all wafers while achieving high productivity
Solution Approach 2:
The patent designs the shaking motion and carrier configuration to ensure homogeneous plating solution distribution across all wafer positions. The motion pattern is specifically designed to eliminate positional variations, ensuring that every wafer in the multi-wafer carrier experiences identical plating conditions, achieving both high productivity and uniform film quality
3Ease of manufacture
If thin Ni film is deposited through deposition or sputtering, then manufacturing cost increases, but film thickness control is improved
Solution Approach 1:
The shaking mechanism compensates for the inherent non-uniformity in electroless plating by dynamically moving the wafers through the plating solution. This motion ensures uniform chemical exposure and replacement reactions across the entire wafer surface, achieving homogeneous thin Ni film deposition at lower cost compared to deposition or sputtering
Solution Approach 2:
The patent optimizes parameters including shaking frequency, plating solution composition, temperature, and immersion time to achieve uniform thin Ni film formation through electroless plating. By carefully controlling these parameters alongside the shaking motion, homogeneous films are obtained at reduced manufacturing cost
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 highly homogeneous Ni film thickness and improved adhesion, reducing manufacturing costs and enhancing productivity by ensuring uniform plating across multiple wafers.
Implementation Method 1
a rectification mechanism including a rectification plate having a plurality of through-holes, the rectification mechanism being held by the carrier in such a manner that the rectification plate faces the target surface of each wafer
Implementation Method 2
a driver configured to shake the carrier as immersed in the bath with a relative positional relationship between each wafer and the plurality of through-holes kept constant
Implementation Method 3
enhancing the flow and diffusion of plating solutions for uniform Ni film deposition
Implementation Method 4
In electroless plating, a single carrier holding a plurality of semiconductor wafers (e.g., 25 semiconductor wafers) is immersed in a bath containing a chemical solution
Implementation Method 5
The surface of the Al-alloy electrode then undergoes deposition using Zn, whose standard oxidation-reduction potential is higher than that of Al, to form a thin Zn film. Subsequently, the Zn film undergoes replacement with Ni
Data Source
AI summary
Provided is a semiconductor-manufacturing apparatus that forms a plated film having a highly homogeneous thickness on a target surface of a semiconductor wafer through electroless plating. A semiconductor-manufacturing apparatus forms plated films on target surfaces of a plurality of wafers held by a carrier capable of holding the wafers. The semiconductor-manufacturing apparatus includes the following: a rectification mechanism including a rectification plate having a plurality of through-holes, the rectification mechanism being held by the carrier in such a manner that the rectification plate faces the target surface of each wafer; a bath in which a chemical solution for forming each plated film is stored, and in which the carrier, holding the plurality of wafers and the rectification mechanism, is immersed in the chemical solution; and a driver configured to shake the carrier as immersed in the bath with a relative positional relationship between each wafer and the through-holes kept constant.