Multi-Zone Foil Heater Assembly for Wafer Temperature Uniformity
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Solution Overview
Problem
Conventional multi-zone temperature control technologies in semiconductor manufacturing fail to achieve precise temperature uniformity on small zones of wafers, leading to abnormal temperature sites and reduced processing efficiency.
Innovation Solution
A multi-zone heating apparatus comprising foil heaters, switches, and a drive control system that uses a ground bus, power supply bus, and control bus to independently control the heating units, reducing the need for external conductive wires and filters, and allowing for precise temperature adjustment in a plasma processing environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional multi-zone temperature control technologies are used with large area heating zones, then the overall temperature control is simplified, but local temperature non-uniformity cannot be effectively solved leading to abnormal temperature sites on the wafer
Solution Approach 1:
The heating system is divided into multiple independently controllable heating zones using foil heaters arranged in an array. Each heating zone can be controlled separately through individual switches, allowing precise local temperature adjustment to eliminate abnormal temperature sites while maintaining overall temperature uniformity across the wafer surface.
Solution Approach 2:
Different regions of the wafer can receive different heating control strategies. The system allows independent temperature control for each heating zone, enabling local quality adjustment where specific areas can be heated or cooled according to their specific process requirements, thereby achieving uniform temperature distribution across the entire wafer.
2Manufacturing precision
If multiple independently controllable heating zones are arranged to satisfy temperature uniformity demands, then temperature control capability is improved, but the large area of heating zones cannot effectively solve local temperature non-uniformity in very small zones
Solution Approach 1:
The heating system is divided into multiple independently controllable heating zones using foil heaters arranged in an array. Each heating zone can be controlled separately through individual switches, allowing precise local temperature adjustment to eliminate abnormal temperature sites while maintaining overall temperature uniformity across the wafer surface.
3Device complexity
If conventional heating systems are integrated between electrostatic chuck and base, then the structure is compact, but externally coupled conductive wires increase leading to increased filter usage
Solution Approach 1:
The heating control system is extracted from the traditional external wiring architecture and integrated directly into the electrostatic chuck structure. The foil heaters and control electronics are embedded within the chuck itself, eliminating the need for multiple external conductive wires and associated filters, thereby simplifying the wiring complexity while maintaining RF environment compatibility.
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
The solution enables effective multi-zone temperature control with reduced external wiring and filter usage, improving temperature uniformity and processing efficiency by allowing for precise control of heating power and duty cycles in each zone.
Implementation Method 1
a plurality of foil heaters; a plurality of switches, wherein each switch is connected with one foil heater to form a heating unit
Implementation Method 2
a plurality of driving wires, each being connected with one switch and configured to transmit a driving signal indicating duty cycle of the switch, such that the switch independently control operating time of the connected foil heater based on the control signal
Data Source
AI summary
Disclosed are a multi-zone heating apparatus, a bottom electrode assembly, a plasma processing apparatus, and a temperature adjusting method, wherein the multi-zone heating apparatus includes: a plurality of foil heaters; a plurality of switches, each switch being connected with a foil heater to form a heating unit; two ends of the plurality of heating units are connected to a ground bus and a power supply bus, respectively; a plurality of driving wires, each driving wire being connected with a switch and configured to transmit a control signal of the duty cycle of the switch, the switches being configured to independently control the operating time of the connected foil heaters based on the control signal. The multi-zone heating apparatus can be integrated between the electrostatic chuck and the base in the plasma processing apparatus and can reduce use of external conductive wires, thereby reducing the demand for filters.