Selective Deposition on Silicon Surfaces via Surface Passivation
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Solution Overview
Problem
Current selective deposition methods for semiconductor manufacturing face challenges in achieving adequate selectivity due to incomplete passivation and physisorption issues during ALD processes, leading to unwanted film deposition on surfaces where it is not desired.
Innovation Solution
A method involving a substrate with a hydroxyl-terminated surface and a hydrogen-terminated surface, where the substrate is treated with a wet chemical composition and heated to convert hydroxyl groups to siloxane groups, followed by exposure to a silicon-containing compound to passivate the surface, allowing selective deposition on the hydrogen-terminated surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ALD deposition processes are used on surfaces with multiple chemical surfaces, then film deposition can occur, but selectivity is insufficient due to incomplete passivation and physisorption of precursor molecules
Solution Approach 1:
The patent applies preliminary action by performing surface passivation treatment before the ALD deposition process. The method involves exposing the substrate to a vapor phase precursor that reacts with surface hydroxyl groups to form a passivation layer, preventing unwanted deposition on certain surfaces before the actual film deposition occurs. This pre-treatment ensures that only desired surfaces are reactive during subsequent ALD processes.
Solution Approach 2:
The patent utilizes parameter changes by controlling the surface chemistry through temperature and chemical exposure conditions. By adjusting the temperature during vapor phase treatment and controlling the exposure to silicon-containing compounds, the surface hydroxyl groups are selectively converted to siloxane groups, changing the surface reactivity parameters to achieve desired selectivity patterns.
2Manufacturing precision
If surface passivation is attempted to prevent unwanted deposition, then selectivity may improve, but physisorption of ALD precursor molecules can still occur leading to film formation on passivated surfaces
Solution Approach 1:
The patent employs a sacrificial hydroxyl layer that is intentionally created and then selectively removed or transformed. The hydroxyl groups serve as temporary reactive sites that are converted to siloxane groups through vapor phase treatment, creating a stable passivation effect. This approach uses the hydroxyl groups as disposable reactive handles that can be selectively activated or deactivated.
Solution Approach 2:
The patent creates composite surface structures by combining different surface terminations (hydroxyl-terminated and hydrogen-terminated surfaces) on the same substrate. This composite surface chemistry allows differential reactivity where silicon-containing precursors selectively react with hydroxyl groups on certain surfaces while leaving hydrogen-terminated surfaces unaffected, achieving spatial selectivity.
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 enhances the selectivity of film deposition, preventing unwanted deposition on passivated surfaces and ensuring precise film formation on the desired surface, thereby improving the manufacturing process for semiconductor devices.
Implementation Method 1
heating the treated substrate at a temperature of from about 200° C. to about 600° C., wherein the heating step converts at least a portion of the surface hydroxyl groups on the first surface to surface siloxane groups
Implementation Method 2
exposing the substrate to a silicon-containing compound in a vapor phase reaction to passivate the first surface of the substrate
Data Source
AI summary
A method is disclosed for delectively depositing a material on a substrate wherein the substrate has at least two different surfaces wherein one surface is passivated thereby allowing selective deposition on the non-passivated surface. In particular, disclosed is a method for preparing a surface of a substrate for selective film deposition, wherein the surface of the substrate comprises at least a first surface comprising SiO2 and an initial concentration of surface hydroxyl groups and a second surface comprising SiH, the method comprising the steps of: contacting the substrate with a wet chemical composition to obtain a treated substrate comprising an increased concentration of surface hydroxyl groups relative to the initial concentration of surface hydroxyl groups; and heating the treated substrate to a temperature of from about 200° C. to about 600° C., wherein the heating step converts at least a portion of the surface hydroxyl groups on the first surface to surface siloxane groups on the surface of the substrate.