Low-Temperature Silicon Oxide Films With Triethylsilane PECVD
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Solution Overview
Problem
Current methods for depositing silicon oxide films at lower temperatures result in films with poor quality, characterized by non-stoichiometric composition, low density, and high etch rates, which are inadequate for electronic applications due to issues such as hydrogen richness and residual silanol incorporation, leading to inferior thermal and electrical performance.
Innovation Solution
The use of triethylsilane as a precursor in plasma-enhanced chemical vapor deposition (PECVD) at temperatures ranging from 25°C to 150°C to produce silicon-containing films with a thickness of 2 nm to 200 nm and a density of 2.2 g/cm³ or greater, achieving stoichiometric or non-stoichiometric silicon oxide or silicon dioxide films with improved density and electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If PECVD is used to deposit silicon oxide films at lower temperatures (400°C or below), then deposition cost and thermal budget are reduced, but film quality deteriorates with non-stoichiometric composition, low density, and fast etch rate
Solution Approach 1:
The patent changes the chemical parameters of the deposition process by using alternative precursors (silane, methylsilane, ethylsilane, propylsilane, butylsilane) instead of TEOS, and adjusts process parameters including deposition temperature (200-400°C), pressure (20-100 mTorr), and oxygen flow rates to achieve stoichiometric SiO2 films with high quality at lower temperatures
Solution Approach 2:
The patent uses simple alkylsilane precursors that are easier to handle and process than TEOS, allowing for lower cost deposition processes while maintaining or improving film quality through optimized deposition conditions
2Shape
If PECVD is used to deposit silicon oxide films at lower temperatures, then gapfill and conformality are improved, but film density and electrical performance deteriorate
Solution Approach 1:
The patent optimizes deposition parameters including using lower pressures (20-100 mTorr), controlling oxygen flow rates (50-200 sccm), and adjusting deposition temperature (200-400°C) to achieve both good conformality and high film density with excellent electrical performance
Solution Approach 2:
The patent replicates the successful film quality characteristics of high-temperature deposited films by using optimized low-temperature PECVD processes with alternative precursors, achieving similar or superior film properties without the thermal budget requirements
3Object-affected harmful factors
If TEOS is used as precursor for PECVD deposition, then safer handling is achieved, but film quality is poor with hydrogen richness and residual silanol incorporation
Solution Approach 1:
The patent uses simple alkylsilane precursors (silane, methylsilane, ethylsilane, propylsilane, butylsilane) that are gases or volatile liquids, replacing liquid TEOS. These precursors decompose more completely during deposition, eliminating residual carbon and hydrogen contamination while achieving stoichiometric SiO2 films with superior quality
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 enables the deposition of high-quality silicon-containing films with enhanced density and reduced hydrogen content, improving the films' electrical and thermal stability, making them suitable for use as gate insulation layers in electronic devices, particularly in low-temperature processing scenarios.
Implementation Method 1
introducing into the reaction chamber triethylsilane as alkylsilane precursor; introducing into the reaction chamber an oxygen source; and depositing by a deposition process the silicon containing film
Data Source
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AI summary
Described herein are low temperature processed high quality silicon containing films. Also disclosed are methods of forming silicon containing films at low temperatures. In one aspect, there are provided silicon-containing film having a thickness of about 2 nm to about 200nm and a density of about 2.2g/cm3 or greater wherein the silicon-containing thin film is deposited by a deposition process selected from a group consisting of chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), cyclic chemical vapor deposition (CCVD), plasma enhanced cyclic chemical vapor deposition (PECCVD, atomic layer deposition (ALD), and plasma enhanced atomic layer deposition (PEALD), and the vapor deposition is conducted at one or more temperatures ranging from about 25°C to about 400°C using an alkylsilane precursor selected from the group consisting of diethylsilane, triethylsilane, and combinations thereof.