Pressure Controlled Heat Pipe for Plasma Chamber Temperature Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor material processing apparatuses face challenges in controlling temperature effectively, particularly with higher process powers, as existing temperature control systems lack the ability to create a variable conductance heat choke between the top and heater plates, affecting etch uniformity and plasma processing results.
Innovation Solution
A showerhead electrode assembly incorporating a pressure controlled heat pipe with a heat transfer liquid and pressurized gas, which creates a variable internal pressure to displace heat transfer liquid between the top and heater plates, allowing for rapid heating and cooling of the showerhead electrode, and maintaining desired temperatures by varying thermal conductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a traditional heater plate is used to preheat the showerhead electrode, then the electrode reaches steady state temperature, but the temperature control precision deteriorates due to inability to create variable conductance heat choke
Solution Approach 1:
The heat pipe system dynamically adjusts thermal conductance between the heater plate and top plate by varying the working fluid pressure. This allows the system to transition between different thermal states (high conductance for heating, low conductance for cooling) to achieve precise temperature control during plasma processing
Solution Approach 2:
The invention changes the physical parameters of the heat pipe system, specifically the pressure of the working fluid, to control thermal conductance. By adjusting pressure, the system can switch between high and low thermal conductance states, enabling precise temperature control without complex additional components
2Speed
If the heater plate directly heats the top plate, then heating efficiency is high, but the ability to rapidly cool and control temperature is reduced
Solution Approach 1:
The heat pipe system provides dynamic thermal management by allowing rapid transition between heating and cooling modes. The variable conductance capability enables the system to quickly respond to temperature control requirements, achieving both fast heating and effective cooling
Solution Approach 2:
The heat pipe acts as an intermediary thermal management device between the heater plate and top plate. It mediates heat transfer by controlling the phase change and pressure of the working fluid, enabling independent control of heating and cooling rates
3Power
If higher process powers are used, then plasma processing efficiency increases, but temperature control stability deteriorates
Solution Approach 1:
The system changes the thermal conductance parameter of the heat pipe by adjusting working fluid pressure, enabling stable temperature control even under varying high power plasma processing conditions. This allows the system to maintain temperature stability across different power levels
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 solution enables precise temperature control of the showerhead electrode, enhancing etch uniformity and response times, allowing for more efficient plasma processing by decoupling the top and heater plates and minimizing energy transfer during preheating, thus improving processing results.
Implementation Method 1
a pressurized gas, which produces a variable internal pressure within the at least one pressure controlled heat pipe
Implementation Method 2
at least one pressure controlled heat pipe secured to an upper surface of the heater plate, the at least one pressure controlled heat pipe having a heat transfer liquid contained therein
Implementation Method 3
the variable internal pressure within the at least one pressure controlled heat pipe during heating of the showerhead electrode by the heater plate displaces the heat transfer liquid from a thermal path between the top plate and the heater plate
Implementation Method 4
the at least one pressure controlled heat pipe having a heat transfer liquid contained therein
Data Source
AI summary
A showerhead electrode assembly for a plasma processing chamber, which includes a showerhead electrode; a heater plate secured to the showerhead electrode; at least one pressure controlled heat pipe secured to an upper surface of the heater plate, the at least one pressure controlled heat pipe having a heat transfer liquid contained therein, and a pressurized gas, which produces a variable internal pressure within the at least one pressure controlled heat pipe; a top plate secured to an upper surface of the at least one heat pipe; and wherein the variable internal pressure within the at least one pressure controlled heat pipe during heating of the showerhead electrode by the heater plate displaces the heat transfer liquid from a thermal path between the top plate and the heater plate, and when removing excess heat from the showerhead electrode returns the heat transfer liquid to the thermal path.