Parallel Flash Lamp Discharge Circuit for Semiconductor Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat treatment apparatuses for semiconductor wafers require a large number of xenon flash lamps and corresponding IGBTs to achieve high-temperature surface heating in a short time, leading to increased costs and space requirements.
Innovation Solution
The heat treatment apparatus includes a chamber, a holder for the substrate, a plurality of flash lamps, a discharge circuit, and a controller. The discharge circuit is configured with M element sets for N parallel-connected flash lamps, where M is an integer less than N, reducing the number of elements needed compared to individual element sets for each flash lamp.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a large number of flash lamps and corresponding IGBTs are provided to achieve high-temperature surface heating in a short time, then the heating capability is improved, but the apparatus costs and installation space increase
Solution Approach 1:
Multiple flash lamps are connected in parallel to a single IGBT, merging the control function into one element. This allows N flash lamps to be controlled by one IGBT, reducing the total number of IGBTs from N to 1, thereby lowering apparatus complexity and cost while maintaining the ability to heat the substrate surface to high temperatures rapidly
2Temperature
If a large number of flash lamps and corresponding IGBTs are provided to achieve high-temperature surface heating in a short time, then the heating capability is improved, but the installation space increases
Solution Approach 1:
The control circuitry for multiple flash lamps is merged into a single IGBT element. By connecting N flash lamps in parallel to one IGBT, the installation space required for control elements is reduced from proportional to N to a constant small amount, thereby reducing overall installation space while maintaining high-temperature heating capability
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 configuration reduces the number of elements in the apparatus, lowering costs and space requirements while maintaining the ability to achieve high-temperature surface heating of semiconductor wafers in a short time.
Implementation Method 1
The wavelength of light emitted from the xenon flash lamps is shorter than that of light emitted from conventional halogen lamps, and approximately coincides with a fundamental absorption band of a silicon semiconductor wafer. Thus, when a semiconductor wafer is irradiated with a flash of light emitted from the xenon flash lamps, the temperature of the semiconductor wafer can be raised rapidly
Implementation Method 2
an insulated-gate bipolar transistor (IGBT) is provided in a discharge circuit for a flash lamp to control the emission of light from the flash lamp. a predetermined pulse signal is inputted to the gate of the IGBT to define the waveform of current flowing through the flash lamp
Data Source
AI summary
An element set including one capacitor, one coil, one thyristor, and one regeneration diode is provided for three parallel-connected flash lamps. The one thyristor collectively effects on-off control of the current flowing through the three corresponding parallel-connected flash lamps. The thyristor is able to suppress a tail current flowing through the flash lamps during flash irradiation. Since a smaller number of element sets than the number of parallel-connected flash lamps are provided, the number of elements provided in a heat treatment apparatus is reduced as compared to the case in which individual element sets are provided for the flash lamps. This suppresses the increase in apparatus costs and reduces the installation space for the elements.