Selective Plasma Oxidation for Dielectric Pre-Clean
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in selectively oxidizing dielectric or semiconductor materials without oxidizing metal materials, leading to increased line, via, or contact resistance, and in cleaning substrates with both metal and dielectric surfaces without damaging one surface while trying to clean the other, often requiring multiple temperature-controlled and chamber-switching processes.
Innovation Solution
A method involving a single-step plasma process using a plasma gas comprising hydrogen, oxygen, and argon at a specific temperature and power range to selectively oxidize dielectric surfaces without oxidizing metal surfaces, and a single-chamber, single-temperature process to clean both dielectric and metal surfaces using a hydrogen-oxygen plasma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If current oxidation processes are used to oxidize dielectric or semiconductor materials, then the dielectric surface is successfully oxidized, but metal materials are also oxidized leading to increased line, via or contact resistance
Solution Approach 1:
The patent applies parameter changes by utilizing microwave plasma technology to create a highly reactive plasma environment with specific power density and temperature control. This allows the oxidation process to selectively affect dielectric materials while preserving metal surfaces, resolving the selectivity contradiction through controlled physical and chemical parameter modification in the plasma state
Solution Approach 2:
The patent employs an inert gas environment (typically argon or nitrogen) as the plasma carrier gas, creating a controlled atmosphere that enables selective oxidation. The inert atmosphere prevents unwanted side reactions and allows precise control over which materials are oxidized, achieving selectivity between dielectric and metal surfaces
2Reliability
If multiple oxidation and reduction reaction processes are used to clean substrate surfaces, then contaminants are removed and surface damage is corrected, but processing time increases and throughput decreases
Solution Approach 1:
The patent merges multiple separate oxidation and reduction processes into a single microwave plasma treatment step. By combining the functions of contaminant removal and surface repair in one unified process using controlled microwave plasma, the patent achieves both high surface cleanliness and improved processing throughput, eliminating the need for sequential multi-step treatments
3Adaptability or versatility
If substrates are transferred between different processing chambers for oxidation and reduction reactions, then different process conditions can be applied, but processing complexity and time increase
Solution Approach 1:
The patent applies universality by designing a single processing chamber capable of performing multiple functions: oxidation, cleaning, and surface modification. The microwave plasma system can be configured with different gas compositions and power levels to achieve various processing outcomes in one chamber, eliminating the need for multiple specialized chambers and reducing system complexity
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 reduces processing time, increases throughput, and maintains the properties of metal surfaces while effectively oxidizing and cleaning dielectric surfaces, thereby addressing the selectivity and efficiency issues in existing methods.
Implementation Method 1
exposing a substrate surface comprising a silicon nitride surface and a tungsten surface to a microwave plasma formed from a plasma gas
Implementation Method 2
selectively oxidize the silicon nitride surface without oxidizing the tungsten surface
Implementation Method 3
exposing a substrate surface having a contaminated dielectric surface and a contaminated metal surface to a plasma formed from a plasma gas
Data Source
AI summary
Method for selectively oxidizing the dielectric surface of a substrate surface comprising a dielectric surface and a metal surface are discussed. Method for cleaning a substrate surface comprising a dielectric surface and a metal surface are also discussed. The disclosed methods oxidize the dielectric surface and/or clean the substrate surface using a plasma generated from hydrogen gas and oxygen gas. The disclosed method may be performed in a single step without the use of separate competing oxidation and reduction reactions. The disclosed methods may be performed at a constant temperature and/or within a single processing chamber.