Flash Annealing Chamber Layout for Particle-Free Wafer Heating
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Solution Overview
Problem
In thermal treatment of semiconductor wafers, flash lamp annealing can contaminate the wafer surface due to particles accumulating on the chamber window and being blown up by high-energy flash light, leading to contamination during the rapid temperature increase process.
Innovation Solution
A thermal treatment apparatus with a chamber separated into upper and lower spaces, featuring a ring support member with a mirrored inner peripheral surface to reflect flash light and prevent particle contamination, and a susceptor configuration to maintain the wafer in a horizontal posture, ensuring that the flash light primarily heats the wafer surface without contaminating it.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If flash lamp annealing is performed to rapidly heat the wafer surface, then impurity activation is achieved without deep diffusion, but particles accumulate on the chamber window and are blown up by high-energy flash light causing contamination
Solution Approach 1:
The patent extracts and removes the chamber window from the direct path of flash light irradiation. By configuring the flash lamp to irradiate the wafer from below through the susceptor rather than from above through a chamber window, the source of particle contamination (the chamber window) is eliminated from the system, allowing rapid annealing without the harmful side effect of particle blow-up and contamination
Solution Approach 2:
The susceptor serves as an intermediary medium that transmits flash light energy to the wafer while preventing particle contamination. The flash light passes through the susceptor to heat the wafer from below, and the susceptor acts as a protective barrier that prevents particles from being blown up and contaminating the wafer surface during the rapid heating process
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
Prevents contamination of the semiconductor wafer by separating the chamber spaces and using a mirrored support to enhance light reflection, allowing for effective and contamination-free rapid temperature increase of the wafer surface during flash lamp annealing.
Implementation Method 1
The wavelength of light emitted by the xenon flash lamp is shorter than the wavelength of light emitted by a conventional halogen lamp, and substantially matches with the basic absorption band of a semiconductor wafer made of silicon. Thus, when emitted onto the semiconductor wafer by the xenon flash lamp, only a small amount of flash light is transmitted, and thus the temperature of the semiconductor wafer rapidly increases.
Implementation Method 2
a ring support member attached to an inner wall surface of the chamber; a plate quartz susceptor supported by the support member
Data Source
AI summary
A ring support is attached to an inner wall surface of a chamber that houses a semiconductor wafer to support a susceptor. When the semiconductor wafer is placed on the susceptor, an inner space of the chamber is separated into an upper space and a lower space. Particles are likely to accumulate on a lower chamber window as a floor part of the chamber. However, since the upper space and the lower space are separated, the semiconductor wafer can be prevented from being contaminated by the particles flowing into the upper space and adhering to a surface of the semiconductor wafer even when the particles on the lower chamber window are blown up by irradiation with flash light.