Flowable SiCN Film Deposition for Void-Free Gap Fill
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Solution Overview
Problem
Conventional semiconductor manufacturing processes face challenges in filling small gaps and trenches with high-quality, void-free films, as existing deposition methods often result in films with poor thermal stability and high etch rates, leading to void formation and shrinkage issues.
Innovation Solution
A cyclic process involving flowable deposition and thermal and ultraviolet treatment is employed, where a substrate undergoes repeated cycles of low-temperature deposition and thermal and UV treatment in separate stations, maintaining a common pressure and using silylamine precursors like hexamethyldisilazane, to achieve a high-quality, void-free SiCN film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition methods are used to fill gaps and trenches, then deposition speed is maintained, but film quality deteriorates with void formation and poor thermal stability
Solution Approach 1:
The deposition process is divided into multiple sequential cycles, each depositing a thin layer followed by immediate thermal and UV treatment. This segmentation allows each layer to be properly cured before the next is added, preventing void formation and ensuring thermal stability throughout the entire film thickness.
Solution Approach 2:
Thermal and UV treatment is applied to each deposited layer before subsequent layers are added. This preliminary curing action ensures that each layer achieves proper adhesion and stability before being covered, preventing future void formation and shrinkage issues.
2Productivity
If conventional deposition methods are used, then deposition can be completed in fewer steps, but film density deteriorates leading to high etch rates
Solution Approach 1:
The process uses cyclic repetition of deposition and treatment steps, changing the temporal parameters of the process. By repeating cycles until desired thickness is achieved, each layer is properly densified through thermal and UV treatment, resulting in high-density film with low etch rates while maintaining overall productivity.
3Manufacturing precision
If low-temperature deposition is used to maintain precursor flowability, then film uniformity improves, but film stability worsens due to poor cross-linking
Solution Approach 1:
Thermal and UV treatment acts as an intermediary step between deposition cycles. This treatment mediates the transition from a uniformly deposited but unstable precursor layer to a stable, cross-linked film structure, enabling both uniformity and stability to coexist.
Solution Approach 2:
The thermal and UV treatment induces phase transitions in the deposited precursor material, transforming it from a metastable, uniformly deposited state to a stable, cross-linked network state. This phase transition occurs at controlled temperatures that preserve uniformity while achieving stability.
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 method effectively fills gaps without voids or seams, improves film stability, and reduces etch rates, enhancing the quality and reliability of semiconductor films.
Implementation Method 1
depositing a flowable material on the substrate in the first station by a vapor deposition process at a first temperature
Implementation Method 2
performing a thermal and ultraviolet treatment on the substrate by heating a surface of the substrate to a second temperature in the second station
Implementation Method 3
exposing the substrate to ultraviolet light
Implementation Method 4
Deposition of flowable sicn films by plasma enhanced atomic layer deposition
Data Source
AI summary
In accordance with some embodiments herein, methods and apparatuses for flowable deposition of thin films are described. Some embodiments relate to cyclical processors for gap-fill in which deposition is followed by a thermal anneal and ultraviolet treatment and repeated. In some embodiments, the deposition, thermal anneal, and ultraviolet treatment are carried out in separate stations. In some embodiments, a second station is heated to a higher temperature than a first station. In some embodiments, a separate module is used for curing.