Dielectric Layer Fabrication via FCVD and Oxygen Plasma
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Solution Overview
Problem
The existing shallow trench isolation (STI) processes in semiconductor manufacturing face challenges such as defects, voids, and surface damage during etching and cleaning processes, leading to current leakage and reduced isolation effectiveness.
Innovation Solution
A method involving chemical mechanical polishing (CMP) followed by a surface treatment with oxygen plasma is employed to form a dielectric layer using flowable chemical vapor deposition (FCVD), which fills high aspect ratio recesses without voids and enhances structural density by crosslinking dangling bonds, thereby improving the dielectric layer's completeness and isolation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CVD process is used to deposit dielectric layer in high aspect ratio recesses, then the recess can be filled, but overhang at top corner and voids are generated
Solution Approach 1:
The patent changes the deposition parameters by using flowable CVD process with controlled flow rate and pressure conditions, allowing the dielectric material to flow into high aspect ratio recesses without forming overhangs or voids, achieving complete filling while maintaining structural integrity
Solution Approach 2:
The patent replaces conventional CVD deposition mechanism with flowable CVD process, where the dielectric material is deposited in a flowable state that can conformally coat the recess walls and fill the entire volume without requiring high temperature or pressure conditions that cause overhang formation
2Productivity
If multiple etching and cleaning processes are performed during manufacturing, then transistor components can be processed, but the exposed STI is damaged forming breaks and spaces
Solution Approach 1:
The patent performs preliminary action by depositing an protective dielectric layer over the STI structure before the multiple etching and cleaning processes, creating a protective barrier that prevents damage to the STI during subsequent manufacturing steps
Solution Approach 2:
The patent provides beforehand cushioning by forming a protective dielectric layer that absorbs and distributes the mechanical and chemical stress from subsequent etching and cleaning processes, preventing direct damage to the STI structure
3Manufacturing precision
If dielectric layer surface is left as-is after CMP process, then planarization is achieved, but surface defects and current leakage occur in subsequent processes
Solution Approach 1:
The patent applies continuous useful action by performing oxygen plasma treatment immediately after the CMP process while the surface is still fresh and reactive, ensuring continuous protection and densification without interrupting the manufacturing flow, thereby preventing surface defects and maintaining isolation effectiveness
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 method effectively prevents defects and surface damage during subsequent processes, ensuring complete filling of recesses and maintaining structural integrity and isolation effectiveness of the dielectric layer.
Implementation Method 1
a surface treatment process is performed on the dielectric layer after the chemical mechanical polishing process, and the surface treatment process includes introducing an oxygen plasma
Implementation Method 2
oxygen radicals into a part of the dielectric layer, therefore, the dangling bonds in the dielectric layer may crosslink
Implementation Method 3
a chemical mechanical polishing (CMP) process is performed on the dielectric layer
Implementation Method 4
Flowable chemical vapor deposition (FCVD) process is performed to form the dielectric layer
Data Source
AI summary
A method of fabricating a dielectric layer includes the following steps. At first, a dielectric layer is formed on a substrate, and a chemical mechanical polishing (CMP) process is performed on the dielectric layer. Subsequently, a surface treatment process is performed on the dielectric layer after the chemical mechanical polishing process, and the surface treatment process includes introducing an oxygen plasma.