In-Situ Oxidation Pre-Treatment for Conformal 3D NAND Memory Holes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High aspect ratio structures in semiconductor devices, such as 3D NAND flash memory, face challenges in achieving conformal oxide growth due to impurity buildup and increased sticking coefficients, leading to non-uniform deposition and reduced processing efficiency.
Innovation Solution
A pre-treatment process involving exposure to a vacuum and treatment with inert gases or hydrogen radicals is applied to the Si-containing surfaces to reduce the sticking coefficient, improving conformality by removing impurities and allowing for air breaks without significant conformality loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the deposition rate is increased to improve processing efficiency, then productivity is improved, but conformality of oxide growth deteriorates due to impurity buildup and increased sticking coefficients
Solution Approach 1:
The patent applies a pre-treatment process before oxide deposition that removes impurities and reduces the sticking coefficient of the silicon-containing surface. This preliminary action prepares the surface to accept oxide growth more uniformly, allowing faster deposition rates without sacrificing conformality. The pre-treatment creates optimal surface conditions that enable subsequent high-rate deposition to maintain uniformity.
Solution Approach 2:
The patent modifies surface parameters through pre-treatment, specifically changing the sticking coefficient and impurity content of the silicon-containing surface. By altering these surface parameters before deposition, the process enables improved conformality even at higher deposition rates, effectively resolving the trade-off between productivity and manufacturing precision.
2Ease of operation
If air breaks are introduced to allow substrate handling, then ease of operation is improved, but conformality deteriorates due to impurity buildup on the surface
Solution Approach 1:
The pre-treatment process is applied after substrate handling and air breaks, creating a corrective action that removes impurities introduced during handling. This allows the process to tolerate air breaks and substrate handling operations while still achieving good conformality, as the pre-treatment cleanses the surface of any contaminants acquired during handling.
Solution Approach 2:
The patent acknowledges that air breaks introduce impurities, but converts this harmful effect into a benefit by using the pre-treatment process to specifically target and remove these impurities. The sticking coefficient reduction from pre-treatment counteracts the impurity buildup from air breaks, allowing easy substrate handling without sacrificing conformality.
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 pre-treatment process enhances the conformality of oxide growth by 4-5%, reducing material buildup and maintaining processing efficiency by ensuring uniform deposition across high aspect ratio structures.
Implementation Method 1
treating the substrate with a pre-treatment gas or plasma
Implementation Method 2
exposing a substrate to a vacuum
Implementation Method 3
oxidizing the substrate while the substrate is still under the vacuum
Data Source
AI summary
Methods of treating a substrate are provided. In some embodiments, the method includes exposing a substrate to a vacuum, wherein the substrate has one or more memory holes or trenches. The method further includes treating the substrate with a pre-treatment gas or plasma. The method includes oxidizing the substrate while the substrate is still under the vacuum. In some embodiments, the one or more memory holes have impurity buildup.