Titanium RF Rod for PECVD Substrate Support
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Solution Overview
Problem
Conventional substrate support assemblies in semiconductor processing chambers experience heat generation issues due to nickel rods, leading to thickness non-uniformity in deposited layers, as they generate hot spots and affect the uniformity of material layers formed on substrates.
Innovation Solution
The substrate support assembly incorporates a rod made of titanium or nickel coated with gold, silver, aluminum, or copper, which reduces heat generation by minimizing electrical resistivity and increasing skin depth, thereby minimizing heat generation as RF current travels through the rod.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nickel rod is used to conduct RF current, then electrical conductivity is achieved, but heat generation increases causing hot spots and thickness non-uniformity
Solution Approach 1:
The patent changes the material parameter of the RF current conducting rod from conventional nickel to titanium or nickel coated with precious metals (gold, silver, aluminum, or copper). This material substitution fundamentally alters the electrical and thermal properties, achieving lower electrical resistivity and reduced heat generation while maintaining adequate conductivity. The coating approach specifically addresses both conductivity enhancement and heat reduction simultaneously.
2Power
If RF current travels through the rod, then power delivery is achieved, but heat generation occurs affecting layer uniformity
Solution Approach 1:
The patent employs composite material structures where a nickel base rod is coated with layers of precious metals (gold, silver, aluminum, or copper). This composite structure combines the adequate conductivity of nickel with the superior surface conductivity and lower heat generation properties of the precious metal coatings, thereby maintaining RF power delivery while improving layer thickness uniformity on the substrate.
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 solution effectively reduces heat generation and minimizes thickness non-uniformity in deposited layers, enhancing the uniformity and quality of material layers formed on substrates during semiconductor processing.
Implementation Method 1
The rod made of Ti or of Ni coated with Au, Ag, Al or Cu has a reduced electrical resistivity
Implementation Method 2
The rod made of Ti or of Ni coated with Au, Ag, Al or Cu has an increased skin depth
Implementation Method 3
Conventionally the rod is made of nickel (Ni), which generates heat
Data Source
AI summary
Embodiments of the present disclosure generally relate to a substrate support assembly in a semiconductor processing chamber. The semiconductor processing chamber may be a PECVD chamber including a substrate support assembly having a substrate support and a stem coupled to the substrate support. An RF electrode is embedded in the substrate support and a rod is coupled to the RF electrode. The rod is made of titanium (Ti) or of nickel (Ni) coated with gold (Au), silver (Ag), aluminum (Al), or copper (Cu). The rod made of Ti or of Ni coated with Au, Ag, Al or Cu has a reduced electrical resistivity and increased skin depth, which minimizes heat generation as RF current travels through the rod.