Selective Si Epitaxy Using Halopolysilane at Lower Temperatures
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving selective epitaxial film growth on substrates with reduced thermal budgets, requiring methods for forming high-quality Si-comprising epitaxial layers at lower temperatures without compromising process throughput.
Innovation Solution
A method and apparatus for forming Si-comprising epitaxial layers using a halopolysilane precursor, allowing selective growth on different single crystalline surfaces at lower temperatures, with a substrate processing apparatus that includes a process chamber, silicon precursor storage, and a controller for executing instructions to manage temperature and pressure, enabling improved growth rates and higher active dopant concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional epitaxial growth methods are used, then high-quality crystalline films can be formed, but high temperatures are required which complicates device integration schemes
Solution Approach 1:
The patent changes the chemical parameters of the precursor material from conventional silicon sources to halopolysilane compounds, which enables epitaxial growth at lower temperatures (400-600°C) while maintaining crystalline film quality. This parameter change in the precursor chemistry directly resolves the contradiction between film quality and temperature requirements
Solution Approach 2:
The use of halopolysilane precursors represents a composite material approach, combining silicon with halogen atoms in a specific molecular structure. This composite precursor enables low-temperature decomposition and selective epitaxial growth, thereby achieving high-quality crystalline films without requiring high temperatures that would complicate device integration
2Adaptability or versatility
If selective epitaxial growth is achieved, then newer device integration schemes can be implemented, but process throughput may be compromised
Solution Approach 1:
The patent achieves selective epitaxial growth by exploiting local differences in crystal orientation on the substrate surface. The halopolysilane precursor decomposes and reacts selectively on specific crystal planes, enabling localized film formation only where needed. This local quality approach allows selective growth for advanced device integration while maintaining overall process efficiency
Solution Approach 2:
The deposition process uses periodic pulsing of the halopolysilane precursor into the reaction chamber, allowing controlled selective growth. This periodic action enables precise deposition on selected crystal orientations while preventing unwanted growth on other surfaces, thereby achieving both selectivity and acceptable throughput for modern device integration schemes
3Temperature
If lower temperature epitaxy is performed, then device integration is simplified, but growth rate decreases
Solution Approach 1:
By changing the precursor from conventional silicon sources to halopolysilane compounds, the patent achieves a parameter change that enables high growth rates at low temperatures. The halopolysilane molecular structure decomposes at lower temperatures with high reactivity, maintaining fast growth kinetics without requiring thermal energy, thus resolving the contradiction between temperature and growth rate
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 solution enables selective epitaxial growth at lower temperatures, improving process throughput and achieving higher active dopant concentrations, which is beneficial for next-generation semiconductor devices, such as buried power rails and source/drain contact formation.
Implementation Method 1
The deposition process may comprise providing, to the process chamber, a Si containing precursor. The Si-containing precursor may be halopolysilane precursor.
Implementation Method 2
performing a deposition process, thereby forming the Si-comprising epitaxial layer on the first exposed surface relative to the second exposed surface
Data Source
AI summary
A method of forming a Si-comprising epitaxial layer selectively on a substrate and a semiconductor processing apparatus is disclosed. Embodiments of the presently described method of forming the Si-comprising epitaxial layer comprise performing a deposition process for forming the Si-comprising epitaxial layer selectively on a first exposed single crystalline surface relative to a second exposed single crystalline surface being different than the first exposed single crystalline surface.