LED Substrate Heater for Rapid Thermal Etching
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Solution Overview
Problem
Conventional semiconductor etching processes, particularly atomic layer etching, face challenges in achieving high selectivity and precision due to the use of plasma, which leads to material damage and reduced selectivity for materials like aluminum dioxide, zirconium dioxide, hafnium dioxide, silicon nitride, and titanium nitride, and struggles with rapid and precise temperature control of substrates.
Innovation Solution
The use of a processing chamber equipped with a pedestal and substrate heater that employs visible light emitting diodes (LEDs) emitting wavelengths between 400 nm and 800 nm for thermal etching, allowing for rapid and precise temperature control of substrates without plasma assistance, and includes a gas distribution unit and temperature sensors for precise control and etching operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma is used for etching, then etching capability is improved, but material damage increases and selectivity decreases
Solution Approach 1:
The patent removes plasma from the etching process entirely, extracting the harmful ion bombardment and reactive species that cause material damage. Instead, it uses pure thermal energy from LEDs to drive etching reactions, achieving plasma-free etching that eliminates the harmful effects while maintaining etching capability
Solution Approach 2:
The patent replaces the plasma-based chemical-mechanical etching system with a thermal-driven chemical etching system. LED-generated heat substitutes for plasma energy, fundamentally changing the etching mechanism from plasma-assisted to purely thermal, thereby eliminating material damage from ion bombardment
2Productivity
If plasma is used for etching, then etching capability is improved, but selectivity decreases
Solution Approach 1:
The patent extracts plasma from the process to eliminate its non-selective chemical reactions and ion bombardment effects. By removing plasma, the etching becomes highly selective because only thermal energy drives the reactions, allowing precise control over which materials are etched based on their thermal response
Solution Approach 2:
The patent changes the energy delivery parameter from plasma (electromagnetic radiation and ion bombardment) to thermal energy (infrared radiation from LEDs). This parameter change enables selective etching because different materials respond differently to thermal energy, allowing precise control over etching selectivity
3Temperature
If conventional heating methods are used, then substrate heating is achieved, but temperature control speed and precision are insufficient
Solution Approach 1:
The patent replaces conventional resistive or conductive heating methods with optical heating using LEDs. This substitution enables rapid temperature control because light energy can be delivered and adjusted instantaneously, allowing fast heating and cooling cycles that conventional methods cannot achieve
Solution Approach 2:
The patent employs periodic pulsed LED operation to achieve precise temperature control. By turning LEDs on and off in controlled pulses, the system can rapidly heat the substrate to desired temperatures and then quickly cool it by stopping the heating, enabling high-speed temperature cycling for advanced etching processes
4Temperature
If conventional heating methods are used, then substrate heating is achieved, but temperature control precision is insufficient
Solution Approach 1:
The patent implements feedback control by monitoring LED power delivery and substrate temperature response. The system adjusts LED power in real-time based on measured temperature, achieving precise temperature control. This closed-loop feedback enables accurate maintenance of target temperatures throughout the etching process
Solution Approach 2:
The patent creates a dynamic temperature control system where LED power can be rapidly adjusted during the process. Unlike static heating methods, the LED system can change power levels instantaneously to respond to process requirements, enabling precise temperature profiling and dynamic optimization of etching conditions
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 efficient and precise thermal etching with improved selectivity and reduced material damage, allowing for faster processing times and higher throughput by using visible light to heat and cool substrates rapidly and uniformly, while maintaining precise temperature control.
Implementation Method 1
a substrate heater having a plurality of light emitting diodes (LEDs) configured to emit light with wavelengths in the range of 400 nanometers (nm) and 800 nm
Implementation Method 2
a window positioned above the substrate heater, having a top surface and a bottom surface opposite the top surface that faces the LEDs, and including a material transparent to light with wavelengths in the range of 400 nm and 800 nm
Implementation Method 3
a unit heater thermally connected to the faceplate such that heat can be transferred between the faceplate and the unit heater
Implementation Method 4
a processing chamber including chamber walls that at least partially bound a chamber interior, and a chamber heater configured to heat the chamber walls
Data Source
AI summary
Apparatuses and methods are described. An apparatus may include a processing chamber including chamber walls, a chamber heater configured to heat the walls, a pedestal positioned within the chamber and including a substrate heater having a plurality of light emitting diodes (LEDs) configured to emit light with wavelengths in the range of 400 nanometers (nm) and 800 nm, a window positioned above the heater and having a material transparent to light with wavelengths in the range of 400 nm and 800 nm, and three or more substrate supports, each having a substrate support surface vertically offset from the window and configured to support a substrate such that the window and the substrate are offset by a nonzero distance.