Semiconductor Film Formation Temperature Control
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Solution Overview
Problem
Existing semiconductor manufacturing methods face challenges in achieving a sharp impurity profile when forming doped and non-doped silicon films sequentially, as impurities diffuse from the doped film into the non-doped film, resulting in broad concentration distributions.
Innovation Solution
A method involving a substrate processing apparatus that forms a first silicon film with impurities at a high temperature and then transitions to a lower temperature to form a second silicon film with reduced or no impurities, using gases like SiH4 and Si2H6, and controlling the temperature and gas flow to inhibit impurity diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a non-doped Si film is formed continuously on a P-doped Si film at the same temperature in the same reaction chamber, then the film lamination sequence is simplified and productivity is improved, but impurity diffusion occurs from the doped film into the non-doped film, resulting in a broad concentration distribution and degraded manufacturing precision
Solution Approach 1:
The patent applies parameter changes by lowering the substrate temperature from the first temperature (used for forming the P-doped Si film) to a second temperature that is lower than the first temperature when forming the non-doped Si film. This temperature reduction suppresses impurity diffusion from the P-doped Si film into the non-doped Si film, thereby achieving a sharp impurity concentration profile while still allowing continuous film formation in the same reaction chamber
Solution Approach 2:
The patent implements dynamics by dynamically adjusting the substrate temperature during the film formation process. The temperature is changed from a first temperature during P-doped Si film formation to a second temperature during non-doped Si film formation. This dynamic temperature control enables the system to optimize both productivity (by maintaining continuous operation) and manufacturing precision (by controlling impurity diffusion through temperature variation)
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 enables the formation of silicon films with sharp impurity profiles, preventing impurity diffusion and maintaining high film quality, while eliminating the need for expensive plasma processing equipment.
Implementation Method 1
a Si wafer is carried (loaded) into a reaction chamber, the temperature inside the reaction chamber is stabilized at 600° C., SiH4 and PH3 are supplied as reactive gases and a P-doped Si film is formed
Implementation Method 2
a non-doped Si film is formed continuously in the same reaction chamber at a temperature of 600° C.
Implementation Method 3
the impurity also diffuses into the non-doped Si film of the upper layer, thereby creating a broad concentration distribution (concentration profile) of the impurity in the non-doped Si film
Data Source
AI summary
A method for manufacturing a semiconductor device includes the steps of: loading a substrate into a reaction chamber; supplying reactive gases into the reaction chamber and processing the substrate; and unloading the processed substrate from the reaction chamber, wherein the step of processing the substrate includes: a first film formation step of setting the substrate to a first temperature and forming a first silicon film including impurity atoms on the substrate and a second film formation step of setting the substrate to a second temperature, which is lower than the first temperature, and forming a second silicon film that includes no impurity atoms or has an impurity concentration lower than that of the first silicon film on at least the first silicon film.