Nozzle Gas Mixing for Boron Doping Uniformity
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Solution Overview
Problem
In semiconductor manufacturing, the thermal decomposition of diborane (B2H6) in high-temperature nozzles of chemical vapor deposition apparatuses leads to the deposition of boron-compound films on nozzle walls, causing inefficiencies in boron doping uniformity and particle generation, as B2H6 is consumed before reaching the substrates.
Innovation Solution
Simultaneously supplying a boron-containing gas (B2H6) and a chlorine-containing gas (HCl) to the nozzles, with a higher concentration of chlorine than boron, to form a compound that suppresses boron deposition on nozzle walls, ensuring uniform boron doping of substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If B2H6 is supplied to the nozzle for boron doping, then boron doping of substrates is achieved, but B2H6 decomposes thermally in the nozzle to form boron-compound films on the inner walls
Solution Approach 1:
The patent introduces HCl gas as an intermediary substance that reacts with B2H6 in the nozzle to form BCl3. This intermediary reaction prevents direct thermal decomposition of B2H6 into boron compounds that deposit on nozzle walls, while still delivering boron to the substrates for doping. The HCl acts as a mediator that transforms the problematic B2H6 decomposition pathway into a controlled chemical reaction pathway.
Solution Approach 2:
The patent changes the chemical composition parameters of the gas mixture by adding HCl to the B2H6 supply. By adjusting the concentration ratio of HCl to B2H6 (with HCl concentration being higher), the chemical reaction pathway in the nozzle is altered from thermal decomposition to chemical conversion, thereby preventing boron compound deposition while maintaining boron delivery to substrates.
2Productivity
If nozzles are disposed at high-temperature region for efficient processing, then substrate processing efficiency is improved, but B2H6 decomposes thermally causing deposition on nozzle walls
Solution Approach 1:
HCl gas serves as an intermediary that enables the system to maintain high nozzle temperatures for efficient substrate processing while preventing the harmful thermal decomposition of B2H6. The intermediary chemical reaction between HCl and B2H6 creates BCl3, which does not deposit as films on the hot nozzle walls, thus allowing high-temperature operation without the harmful deposition effect.
Solution Approach 2:
The patent converts the harmful thermal decomposition of B2H6 into a beneficial chemical reaction with HCl. The high temperature that would normally cause problematic decomposition is instead utilized to drive the desired chemical conversion of B2H6 and HCl into BCl3, which then delivers boron to substrates without forming depositing compounds on the nozzle.
3Manufacturing precision
If multiple nozzles are installed at upstream and downstream sides for uniform doping, then inter-wafer boron concentration uniformity is improved, but B2H6 consumption in nozzles increases causing particle generation
Solution Approach 1:
By introducing HCl as an intermediary, the patent enables multiple nozzles to operate simultaneously at high temperatures without generating boron compound deposits. The HCl-B2H6 reaction pathway prevents the formation of depositing boron compounds in all nozzles, thereby eliminating the particle generation problem that would otherwise result from having multiple nozzles in high-temperature regions.
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 prevents boron-compound film formation on nozzle walls, maintains boron doping uniformity, and reduces particle generation, allowing for effective boron doping of substrates even at high temperatures.
Implementation Method 1
simultaneously supplying at least a boron-containing gas as a constituent element and a chlorine-containing gas as a constituent element to a gas supply nozzle... to generate a compound containing the boron and the chlorine in the gas supply nozzle
Implementation Method 2
forming boron-doped silicon films on the plurality of substrates by doping each of the plurality of substrates with the boron contained in the compound
Data Source
AI summary
Formation of a boron compound is suppressed on the inner wall of a nozzle disposed in a high-temperature region of a process chamber. A semiconductor device manufacturing method comprises forming a boron doped silicon film by simultaneously supplying at least a boron-containing gas as a constituent element and a chlorine-containing gas a constituent element to a gas supply nozzle installed in a process chamber in a manner that concentration of chlorine (Cl) is higher than concentration of boron in the gas supply nozzle.