Blocking Molecules for High-Temperature Selective Epi Deposition
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Solution Overview
Problem
Current selective epitaxial deposition processes are not amenable to higher-temperature silicon deposition due to the inability of existing blocking molecules to withstand temperatures above 400 degrees Celsius, which limits the scalability and complexity of semiconductor device manufacturing.
Innovation Solution
A method involving the use of a blocking layer comprising molecules of the formula Xz—Si—Y(4-z), where X is alkyl, aryl, or aralkyl, and Y is halide or alkoxy, which can withstand temperatures from 400 to 650 degrees Celsius, allowing for selective epitaxial silicon deposition on mixed-surface substrates by preventing deposition on dielectric surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If existing blocking molecules are used for selective epitaxial deposition, then deposition on dielectric surfaces can be prevented at lower temperatures, but the process cannot be sustained at higher temperatures (400-650 degrees Celsius)
Solution Approach 1:
The patent changes the chemical parameters of the blocking molecules by introducing silicon-based molecular structures with specific functional groups that remain stable at high temperatures. The blocking molecules are designed with silicon-oxygen-silicon bonding configurations that maintain their blocking capability throughout the high-temperature epitaxial deposition process, resolving the contradiction between temperature increase and blocking layer stability.
2Productivity
If higher temperature deposition is implemented to improve device performance, then processing window is expanded, but existing blocking chemistries fail to maintain selectivity
Solution Approach 1:
The patent employs composite blocking molecule structures that combine silicon-based backbones with specific functional groups. These composite molecular structures provide both thermal stability for high-temperature processing and chemical selectivity for precise deposition control, enabling simultaneous achievement of improved productivity and manufacturing precision.
3Productivity
If the number of vertical layers is increased to achieve miniaturization, then circuit density improves, but process complexity and difficulty of selective deposition increase
Solution Approach 1:
The silicon-based blocking molecules automatically self-assemble and self-regenerate during the high-temperature epitaxial process. The silicon-oxygen-silicon bonding structure enables the blocking layer to self-maintain its integrity and blocking function throughout multiple deposition cycles, reducing process complexity for multi-layer fabrication while supporting higher circuit densities.
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
Enables selective epitaxial silicon deposition at higher temperatures, improving the processing window for semiconductor fabrication and allowing for the fabrication of multiple devices with enhanced performance and complexity, while maintaining the integrity of silicon-based material surfaces.
Implementation Method 1
depositing a blocking layer on the exposed dielectric material... preventing deposition on dielectric surfaces
Implementation Method 2
epitaxially and selectively depositing a silicon-containing material layer on the exposed silicon-based material
Implementation Method 3
exposing a substrate including an exposed dielectric material and an exposed silicon-based material to a plasma pre-clean process
Data Source
AI summary
Implementations described herein generally relate to processes for the fabrication of semiconductor devices in which a blocking layer of molecules is used to achieve selective epitaxial deposition. In one implementation, a method of processing a mixed-surface substrate comprising an exposed dielectric material and an exposed silicon-based material is provided. The method comprises depositing a blocking layer on the exposed dielectric material and epitaxially and selectively depositing a silicon-containing material layer on the exposed silicon-based material at a temperature of 400 degrees Celsius or greater. The method further involves removing the blocking layer from the dielectric material.