Substrate Processing Exhaust Ports for Selective Epitaxy
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Solution Overview
Problem
Existing selective epitaxy processes face challenges in maintaining selectivity due to uncontrolled reaction conditions, such as temperature and precursor concentrations, leading to inefficient deposition of epitaxial and polycrystalline materials, and are limited by high reaction temperatures that cause nitridation and thermal issues.
Innovation Solution
A substrate processing apparatus and method that includes a lower chamber with exhaust ports and nozzles to effectively manage reaction gases and byproducts, preventing deposition within the chamber and maintaining controlled pressure and gas flow to optimize the epitaxial process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high reaction temperature is used for selective epitaxy process, then deposition rate is improved, but nitridation reaction and thermal damage occur on substrate surface
Solution Approach 1:
The patent applies parameter changes by transitioning from high temperature thermal epitaxy to low temperature plasma-enhanced epitaxy. The reaction temperature is reduced from approximately 800-1000°C to below 450°C, while maintaining high deposition rates through plasma activation. This parameter change resolves the contradiction by enabling fast deposition without the harmful thermal effects that occur at high temperatures.
Solution Approach 2:
The patent replaces the thermal field (mechanical heating system) with a plasma field (electromagnetic field) to drive the epitaxial reaction. Instead of relying on high temperature thermal energy to enable deposition, the invention uses plasma-generated reactive species and ion bombardment to facilitate chemical reactions at low temperatures, thereby achieving high productivity without thermal damage.
2Productivity
If insufficient silicon precursor is supplied, then etching reaction is activated to decrease whole process rate, but if sufficient silicon precursor is supplied, then deposition efficiency improves
Solution Approach 1:
The patent changes the chemical parameters of the precursor gases and their flow ratios to optimize the deposition-etching balance. By adjusting the silicon precursor concentration and using plasma activation, the system achieves high deposition efficiency while suppressing etching reactions that would otherwise occur with insufficient precursor supply.
Solution Approach 2:
The patent replaces thermal reaction control with plasma-controlled chemical reactions. The plasma environment enables precise control over reaction pathways, allowing silicon precursors to deposit efficiently as epitaxial material rather than undergoing unwanted etching reactions, even at low temperatures.
3Manufacturing precision
If insufficient corrosive solution precursor is supplied, then selectivity for forming single crystalline and polycrystalline materials is reduced, but if sufficient corrosive solution precursor is supplied, then selectivity improves
Solution Approach 1:
The patent optimizes the chemical composition and concentration parameters of the corrosive precursor gases. By carefully controlling the ratio and partial pressure of chlorinated or fluorinated hydrocarbon precursors in the plasma, the system achieves high selectivity for forming single crystalline versus polycrystalline regions while maintaining efficient precursor utilization.
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 precise control over the epitaxial process, improving selectivity and reducing thermal and nitridation issues, allowing for efficient deposition of epitaxial and polycrystalline materials while preventing reaction gas deposition within the chamber.
Implementation Method 1
at least one exhaust nozzle disposed along the inner wall of the external reaction tube, the at least one exhaust nozzle having an exhaust hole for suctioning an non-reaction gas and byproducts within the process space
Implementation Method 2
at least one supply nozzle disposed along an inner wall of the external reaction tube, the at least one supply nozzle having a supply hole for discharging a reaction gas
Implementation Method 3
selective epitaxy processes involve deposition reaction and etching reaction... the epitaxial layer is formed on a surface of a single crystal
Data Source
AI summary
A substrate processing method in which processes with respect to substrates are performed comprises: stacking the substrates on a substrate holder disposed in a staking space formed within a lower chamber through a passage formed in a side of the lower chamber, exhausting the stacking space through an auxiliary exhaust port connected to the stacking space, moving the substrate holder into an external reaction tube closing an opened upper side of the lower chamber to provide a process space in which the processes are performed, and supplying a reaction gas into the process space using a supply nozzle connected to the process space and exhausting the process space using an exhaust nozzle connected to the process space and an exhaust port connected to the exhaust nozzle.