Tin Plating Solution Grain Refiner for Semiconductor Bumps
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Solution Overview
Problem
As semiconductor devices shrink, the reliability of connection terminals formed through electroplating methods is compromised due to larger grain sizes of plated bumps, leading to surface roughness and processing inefficiencies.
Innovation Solution
A tin plating solution comprising tin ions, aliphatic sulfonic acid, an anti-oxidant, a polycyclic aromatic wetting agent, and an aromatic carbonyl grain refiner is used to reduce grain size and improve the reliability of semiconductor device bumps, with the grain refiner adjusting the tin layer's grain size and preventing whisker growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional electroplating methods are used to form connection terminals, then plating speed can be increased, but grain size of plated bumps increases leading to surface roughness and reduced reliability
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition of the plating solution, specifically incorporating grain refiners (aromatic carbonyl compounds) and wetting agents (polycyclic aromatic compounds) at controlled concentrations. These chemical parameter changes enable fine-grained bump formation even at high plating speeds, resolving the contradiction between productivity and manufacturing precision
Solution Approach 2:
The patent uses composite plating solution formulation combining multiple functional components: tin ions, aliphatic sulfonic acid, anti-oxidants, wetting agents, and grain refiners. This composite approach creates synergistic effects that simultaneously achieve high plating speed and fine grain structure, overcoming the trade-off between productivity and precision
2Productivity
If plating speed is increased to improve productivity, then manufacturing efficiency improves, but surface smoothness deteriorates due to larger grain sizes
Solution Approach 1:
The patent changes chemical parameters of the plating solution by adding grain refiners (e.g., benzocyclopentadiene, acetophenone) at specific concentrations (0.01-10 g/L). These parameter modifications suppress grain growth during high-speed plating, maintaining surface smoothness while achieving high productivity
Solution Approach 2:
The grain refiner acts as an intermediary substance that mediates between the conflicting requirements of high plating speed and surface smoothness. The aromatic carbonyl compound interferes with grain boundary migration and crystal growth, enabling fine-grained structure formation even under high-current-density conditions that would normally produce rough surfaces
3Manufacturing precision
If grain size is reduced to improve surface smoothness and reliability, then manufacturing precision improves, but plating speed decreases
Solution Approach 1:
The patent modifies plating solution parameters by incorporating wetting agents (polycyclic aromatic compounds with specific molecular structures) that enhance surface activity and promote uniform nucleation. This enables fine grain formation without sacrificing plating speed, as the wetting agent facilitates rapid and uniform metal deposition across the substrate surface
Solution Approach 2:
The plating solution formulation achieves multi-functionality by combining components that simultaneously control grain size, maintain surface smoothness, and sustain high plating speed. The synergistic interaction between grain refiners, wetting agents, and electrolyte components creates a universal solution that addresses multiple conflicting requirements at once
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 results in smaller grain sizes of tin bumps, enhancing surface smoothness and increasing plating speed, thereby improving the reliability and efficiency of semiconductor device fabrication.
Implementation Method 1
a grain refiner that is an aromatic carbonyl compound... The grain refiner is expressed by Formula 1 below... a concentration of the grain refiner is 0.01 to 10 g/L
Implementation Method 2
a wetting agent that is a polycyclic aromatic compound... The polycyclic aromatic compound is expressed by Formula 2 below... a concentration of the wetting agent is 1 to 200 g/L
Implementation Method 3
an aliphatic sulfonic acid having a carbon number of 1 to 10... a concentration of the aliphatic sulfonic acid is 225 to 350 ml/L
Implementation Method 4
an anti-oxidant... The anti-oxidant comprises one of hydroquinone and orange acid
Implementation Method 5
tin ions supplied from a soluble tin electrode
Data Source
AI summary
A tin plating solution and a method for fabricating a semiconductor device are provided. The tin plating solution comprises tin ions supplied from a soluble tin electrode, an aliphatic sulfonic acid having a carbon number of 1 to 10, an anti-oxidant, a wetting agent, and a grain refiner that is an aromatic carbonyl compound.