CMP Gap-Fill Oxidizer Treatment for Scratch Defect Reduction
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Solution Overview
Problem
The increasing aspect ratio of deep trenches in FinFET formation during semiconductor manufacturing makes it difficult to fill with dense gap-fill materials, leading to scratch defects during chemical mechanical planarization (CMP) and poor adhesion between layers, which can cause leakage, shorts, and other issues in IC products.
Innovation Solution
Treating the lower density gap-fill material with a thermally controlled aqueous oxidizer to enhance its hardness and adhesion with a higher density material before CMP, reducing scratch defects and improving layer adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If low density gap-fill material is used to fill deep trenches with high aspect ratio, then the trenches can be filled properly, but scratch defects occur during CMP processes
Solution Approach 1:
A preparatory treatment step is introduced before CMP to modify the gap-fill material surface. This preliminary action enhances the material properties in advance, making it more resistant to scratch defects during the subsequent CMP process without changing the material's ability to fill deep trenches
Solution Approach 2:
The physical or chemical parameters of the gap-fill material are modified through treatment (such as plasma treatment, chemical vapor deposition, or thermal processing) to alter its surface properties. This changes the material's hardness, adhesion, or other characteristics to reduce scratch defect formation during CMP while maintaining its low-density filling capability
2Reliability
If two or more layers of gap-fill materials are deposited to meet low wet etch rate requirements, then etch rate requirements are satisfied, but adhesion between adjacent films deteriorates
Solution Approach 1:
An intermediary treatment or intermediate layer is introduced between the multiple gap-fill material layers to improve interlayer adhesion. This intermediary element acts as a bridge that enhances bonding between adjacent films while allowing each layer to maintain its required wet etch rate characteristics
Solution Approach 2:
The deposition parameters, material composition, or post-deposition treatment parameters are adjusted to optimize both adhesion and etch rate properties. By carefully controlling these parameters, the patent achieves good interlayer adhesion while maintaining the low wet etch rate requirement for each layer
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
Significantly reduces CMP scratch defects by 50% to 75% and enhances adhesion between layers, maintaining the integrity of IC products while being cost-effective and integratable with existing manufacturing flows.
Implementation Method 1
treating the lower density gap-fill material with a thermally controlled aqueous oxidizer to enhance its hardness
Implementation Method 2
treating the lower density gap-fill material with a thermally controlled aqueous oxidizer
Data Source
AI summary
Disclosed is a method of forming a semiconductor device. The method includes providing a precursor having a substrate and protrusions over the substrate. The protrusions are interposed by trenches. The method further includes depositing a first dielectric layer over the protrusions and filling the trenches. The first dielectric layer has a first hardness. The method further includes treating the first dielectric layer with an oxidizer. The method further includes performing a chemical mechanical planarization (CMP) process to the first dielectric layer.