Self-Limiting Silicon Deposition on III-V Substrates
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Solution Overview
Problem
Current silicon deposition methods, such as ALD and PVD, are inefficient at low temperatures and incompatible with three-dimensional semiconductor devices like finFETs, and fail to provide self-limiting and saturating silicon growth on non-silicon surfaces.
Innovation Solution
Cycling dosing of silane and chlorosilane precursors at temperatures between 50° C. and 300° C. to form a self-limiting silicon monolayer on substrates like InxGa1-xAs, InxGa1-xSb, InxGa1-xN, and SiGe, with Si—H termination for continued growth and passivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional ALD or PVD methods are used for silicon deposition, then silicon layers can be formed on substrates, but the process requires high temperatures (above 355°C) and is incompatible with three-dimensional semiconductor devices
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperatures (>355°C) to low temperatures (50-300°C) by using a self-limiting cyclic deposition process with silane and chlorosilane precursors, enabling deposition on temperature-sensitive 3D semiconductor devices without requiring high thermal energy
Solution Approach 2:
The patent segments the continuous deposition process into discrete cyclic steps: dosing silane precursor, purging, dosing chlorosilane precursor, and purging again. Each cycle deposits a controlled amount of silicon, allowing precise thickness control and compatibility with complex 3D device geometries
2Manufacturing precision
If conventional ALD processes are used for monolayer silicon growth, then silicon layers can be deposited, but each cycle takes several minutes and the process is slow
Solution Approach 1:
The patent achieves continuous useful action by using self-limiting surface reactions where each precursor cycle completely saturates the surface sites. The cyclic dosing of silane followed by chlorosilane continuously deposits silicon monolayers without idle time, as each cycle immediately prepares the surface for the next cycle, eliminating waiting periods while maintaining precise monolayer control
Solution Approach 2:
The patent uses periodic cyclic dosing of precursors with optimized timing. Each cycle consists of silane dosing, purging, chlorosilane dosing, and purging, creating a rhythmic deposition process that maintains high productivity while ensuring complete surface coverage and monolayer precision through repeated periodic cycles
3Reliability
If PVD deposition of silicon is used for passivation, then silicon can be deposited, but the silicon is not ordered and requires multilayer structures
Solution Approach 1:
The patent employs self-service through self-limiting surface reactions where the deposition process automatically terminates when all surface sites are saturated with silicon. The cyclic dosing of silane and chlorosilane precursors naturally stops depositing when the surface is fully covered, creating ordered monolayers without requiring complex multilayer structures or external control mechanisms
4Temperature
If low temperature deposition is attempted with conventional methods, then temperature requirements are reduced, but the deposition process becomes inefficient and HCl desorption is slow
Solution Approach 1:
The patent changes the chemical parameters by using silane and chlorosilane precursors with self-limiting surface reactions. This allows low temperature operation (50-300°C) while maintaining high deposition efficiency, as the cyclic dosing mechanism ensures complete surface saturation without requiring high temperature to drive off HCl, unlike conventional continuous processes
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
Achieves low-temperature self-limiting and saturating silicon deposition on various substrates, enabling efficient surface preparation and passivation, suitable for semiconductor and metal surfaces, and providing protection against oxidation.
Implementation Method 1
Self-limiting chemical vapor deposition and atomic layer deposition methods
Implementation Method 2
Self-limiting chemical vapor deposition and atomic layer deposition methods
Implementation Method 3
cycling dosing of silane and chlorosilane precursors at a temperature between 50° C. and 300° C.
Data Source
AI summary
Methods for depositing silicon on a semiconductor or metallic surface include cycling dosing of silane and chlorosilane precursors at a temperature between 50° C. and 300° C., and continuing cycling between three and twenty three cycles until the deposition self-limits via termination of surface sites with Si—H groups. Methods of layer formation include depositing a chlorosilane onto a substrate to form a first layer, wherein the substrate is selected from the group consisting of InxGa1-xAs, InxGa1-xSb, InxGa1-xN, SiGe, and Ge, wherein X is between 0.1 and 0.99. The methods may include pulsing a silane to form a silicon monolayer and cycling dosing of the chlorosilane and the silane. Layered compositions include a first layer selected from the group consisting of InxGa1-xAs, InxGa1-xSb, InxGa1-xN, SiGe, and Ge, wherein X is between 0.1 and 0.99, and a second layer, wherein the second layer comprises Si—H and Si—OH.