Filament Segmentation for Uniform Substrate Heating
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Solution Overview
Problem
Conventional electron impact heating apparatuses for semiconductor substrates suffer from non-uniform temperature distribution due to the directional emission of thermoelectrons, leading to inconsistent heating and low yield in semiconductor devices, especially when heating large-diameter substrates.
Innovation Solution
The substrate heating apparatus features a filament with inner and outer peripheral portions arranged in a specific pattern to uniformly emit thermoelectrons onto the substrate, using a conductive heater and acceleration power supply to improve temperature distribution, with the filament connected to a power supply and acceleration power source to generate and direct thermoelectrons effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional single-loop or multiple-coil filament is used to heat the substrate, then the substrate can be heated to high temperature, but the temperature distribution on the substrate becomes non-uniform
Solution Approach 1:
The filament is divided into multiple independent heating zones (first, second, third heating zones) arranged in a specific pattern. Each zone can be independently controlled to emit thermoelectrons toward different regions of the substrate, enabling uniform temperature distribution across the entire substrate surface while maintaining high temperature.
2Device complexity
If thermoelectrons are emitted in all directions from the filament, then the filament structure is simple, but the temperature distribution on the substrate becomes non-uniform due to electrons converging on the center
Solution Approach 1:
Different segments of the filament are positioned and oriented to emit thermoelectrons toward specific regions of the substrate. The first heating zone emits electrons toward the center, the second toward the edge, and the third toward the diagonal region, creating locally optimized electron emission patterns that collectively achieve uniform global temperature distribution.
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 enhances the uniformity of thermoelectron emission, resulting in improved temperature distribution across the substrate, reducing temperature differences and increasing the yield of semiconductor devices by ensuring more consistent annealing characteristics.
Implementation Method 1
a filament arranged in the conductive heater and connected to a filament power supply to generate thermoelectrons
Implementation Method 2
an acceleration power supply which accelerates the thermoelectrons between the filament and the conductive heater
Implementation Method 3
an electron impact heating apparatus in which thermoelectrons are generated by a single-loop or multiple-coil filament arranged in a vessel placed in a vacuum, and are caused to collide to generate heat
Data Source
AI summary
A substrate heating apparatus having a conductive heater which heats a substrate includes a filament arranged in the conductive heater and connected to a filament power supply to generate thermoelectrons, and an acceleration power supply which accelerates the thermoelectrons between the filament and conductive heater. The filament has inner peripheral portions formed at a predetermined interval along an inner circle concentric with the substrate, outer peripheral portions formed at a predetermined interval on an outer circle concentric with the inner circle and having a diameter larger than that of the inner circle, and a region formed by connecting the end point of each inner peripheral portions and the end point of a corresponding one of the outer peripheral portions.