Semiconductor Substrate Surface Cleaning via Adsorbate Displacement
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Solution Overview
Problem
Existing semiconductor device fabrication methods face challenges in removing oxygen-containing species from substrate surfaces before material layer deposition, which can disrupt epitaxial growth and alter electrical properties due to limitations in pre-deposition etch and bake processes.
Innovation Solution
A method involving a preclean module for exposing substrates to a fluorine-containing etchant, followed by a deposition module where substrates are exposed to an adsorbate like arsine or phosphine to displace and prevent oxygen-containing species, ensuring a clean surface for material layer deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a pre-deposition etch operation is performed to remove oxygen-containing species from the substrate surface, then the surface cleanliness is improved, but additional oxygen-containing species may become resident on the surface subsequent to precleaning due to queuing within the semiconductor processing system
Solution Approach 1:
The substrate is exposed to the adsorbate in the deposition module before material layer deposition to preemptively displace oxygen-containing species that may have become resident on the surface during queuing and transfer operations, ensuring the surface is clean at the moment of deposition
Solution Approach 2:
An adsorbate is introduced as an intermediary substance that temporarily occupies surface sites and displaces oxygen-containing species, acting as a mediator between the preclean etch operation and the subsequent material layer deposition to prevent re-contamination
2Manufacturing precision
If a pre-deposition bake operation is performed to remove oxygen-containing species from the substrate surface, then the surface cleanliness is improved, but the temperature and duration are limited by the thermal budget associated with the semiconductor device being fabricated
Solution Approach 1:
The method changes the approach from thermal removal of oxygen-containing species to chemical displacement using adsorbate exposure, allowing surface cleaning without exceeding the thermal budget constraints of the semiconductor device fabrication process
3Ease of manufacture
If the substrate is transferred through a semiconductor processing system atmosphere between precleaning and deposition, then the substrate can be processed in a practical manufacturing system, but oxygen-containing species become resident on the substrate surface during transfer
Solution Approach 1:
The adsorbate exposure is performed as a preliminary action immediately before material layer deposition in the deposition module, counteracting oxygen-containing species that accumulated during the necessary transfer operations through the processing system
Solution Approach 2:
The substrate remains continuously supported and processed through the system from precleaning through adsorbate exposure to deposition, maintaining practical manufacturability while the adsorbate exposure continuously protects the surface from oxygen-containing species during the transfer interval
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 effectively limits interfacial oxygen incorporation, enhancing the quality of material layers by maintaining pristine growth surfaces and improving electrical properties.
Implementation Method 1
exposing the substrate to a preclean etchant while supported within the preclean module
Implementation Method 2
exposed to an adsorbate while supported within the deposition module
Implementation Method 3
A material layer is the deposited onto the substrate while supported within the deposition module subsequent to exposing the substrate to the adsorbate
Data Source
AI summary
A material layer deposition method includes supporting a substrate in a preclean module and exposing the substrate to a preclean etchant while supported within the preclean module. The substrate is transferred to a deposition module and exposed to an adsorbate while supported within the deposition module. A material layer is the deposited onto the substrate while supported within the deposition module subsequent to exposing the substrate to the adsorbate. Semiconductor processing systems and computer program products are also described.