Plasma Processing Electrodes for Etching Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional plasma processing techniques face challenges in achieving uniform etching rates across the wafer surface due to non-uniform ion energy distribution and byproduct concentration, leading to issues like etch stop, over-etch, and reduced yield, especially in advanced semiconductor manufacturing processes.
Innovation Solution
A plasma processing apparatus with electrodes on the center and peripheral sides of the sample stage, where radio frequency power is supplied with alternating large and small amplitudes, and the duration and ratio of these amplitudes are adjusted to optimize etching uniformity, allowing for precise control of etching depth and rate across the wafer surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional plasma processing is used with single electrode configuration, then the processing is simple, but the etching rate uniformity across wafer surface deteriorates
Solution Approach 1:
The single electrode is divided into multiple electrodes (first electrode and second electrode) positioned at different locations within the processing chamber. Each electrode can be independently controlled to generate plasma with different characteristics, allowing separate optimization of etching rates in different regions of the wafer surface.
Solution Approach 2:
Different electrodes are configured with different properties (positioning, power supply, gas flow) to create localized plasma regions with tailored characteristics. This enables different parts of the wafer to receive plasma with optimal properties for their specific location, achieving uniform etching across the entire surface.
2Productivity
If radio frequency power is supplied to improve etching rate, then the etching speed increases, but the uniformity of ion energy distribution deteriorates
Solution Approach 1:
The radio frequency power supply is segmented into multiple independent channels, each connected to a specific electrode. This allows independent control of power distribution to different regions, enabling high overall etching rates while maintaining uniform ion energy through localized adjustment.
Solution Approach 2:
The power supply parameters (frequency, amplitude, phase) are independently adjusted for each electrode to optimize the plasma characteristics. By changing these parameters locally, the system achieves both high etching rates and uniform ion energy distribution across the wafer surface.
3Adaptability or versatility
If multiple etching processes are used for advanced semiconductor manufacturing, then the processing capability increases, but the accumulation of uniformity deterioration worsens
Solution Approach 1:
The plasma processing system is segmented into multiple independently controllable electrode units, each capable of performing different etching functions. This segmentation allows complex multi-step etching processes to be executed with uniformity control at each step, preventing accumulation of uniformity deterioration.
Solution Approach 2:
The system incorporates monitoring and control mechanisms that provide feedback on etching uniformity across the wafer surface. This feedback enables real-time adjustment of electrode parameters to maintain uniformity even during multiple sequential etching processes required for advanced semiconductor manufacturing.
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 enhances the uniformity of etching rates from the center to the periphery of the wafer, improving the yield and precision of semiconductor devices by minimizing variations in electrical characteristics and performance across the wafer surface.
Implementation Method 1
The electric field or the magnetic field supplied by the generation means excites the process gas and brings about a plasma state. As a result, plasma is formed in a space over the sample stage in the processing chamber.
Implementation Method 2
The electric field or the magnetic field supplied by the generation means excites the process gas and brings about a plasma state.
Implementation Method 3
The electric field or the magnetic field supplied by the generation means excites the process gas and brings about a plasma state.
Implementation Method 4
a bias potential depending upon potential of plasma is formed over the sample. As a result, charged particles in the plasma are attracted to the top surface of the sample to collide with the top surface.
Data Source
AI summary
A plasma processing apparatus includes a sample stage disposed in a processing chamber within a vacuum chamber. A wafer mounted on a top surface of the sample stage is processed by using plasma formed in the processing chamber. The plasma processing apparatus further includes electrodes disposed on a part on a center side and a part on a peripheral side within the sample stage and supplied with radio frequency power. Large amplitude and small amplitude are repeated with a predetermined period in each of the radio frequency powers supplied respectively to the electrode on the center side and the electrode on the peripheral side. A control apparatus adjusts a length of large amplitude term, or the length of the large amplitude term and a ratio of the length to a period in each of the radio frequency powers to different values.