Sectorized Annular Baffle Plate for Wafer Etching Uniformity
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Solution Overview
Problem
Existing gas baffle designs in plasma-based processing chambers fail to achieve uniform plasma distribution and etching uniformity, particularly in high-standard processes like through-silicon via and deep silicon etching, due to their isotropic nature and fixed inner diameters, which do not account for the layout of gas inlets, outlets, and RF inlets.
Innovation Solution
A gas baffle plate with an annular shape featuring varying inner radii in different sectors, designed based on the positions of gas inlets, outlets, and RF inlets, to optimize plasma distribution and compensate for non-uniformities in the process chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an isotropic gas baffle plate with fixed inner diameter is used, then the device structure is simple and easy to manufacture, but the plasma distribution uniformity and etching uniformity are poor
Solution Approach 1:
The baffle plate is divided into multiple sectors with different inner radii tailored to local plasma distribution requirements. Each sector's inner radius is specifically designed based on the position of gas inlets, outlets, and RF inlets to optimize plasma uniformity in that particular region, thereby achieving overall etching uniformity across the wafer surface.
Solution Approach 2:
The baffle plate transitions from a symmetric isotropic design to an asymmetric anisotropic design where the inner radius varies by sector. This asymmetric configuration compensates for the non-uniform plasma distribution caused by the specific layout of gas and RF components, improving etching uniformity without requiring complex active control systems.
2Manufacturing precision
If the baffle plate inner diameter is optimized for specific layouts, then the plasma distribution uniformity improves, but the device becomes more complex and harder to manufacture
Solution Approach 1:
The baffle plate is segmented into multiple discrete sectors, each with a specific inner radius value. This segmentation allows the complex anisotropic design to be broken down into simpler, manufacturable segments that can be fabricated using standard techniques, reducing overall manufacturing difficulty while maintaining plasma uniformity benefits.
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
Improves etching uniformity by up to 12.6% compared to 23.3%, meeting stringent uniformity standards in TSV and deep silicon etching processes.
Implementation Method 1
Plasma based processing techniques have gained widespread use in fabrication of devices
Implementation Method 2
A gas baffle plate may include a gas inlet, a gas outlet, and a radio frequency (RF) inlet
Data Source
AI summary
A method for making a process chamber having a baffle plate therein is provided. In some embodiments, the method includes determining a first position of a radio frequency (RF) inlet of the process chamber, in which the RF inlet is configured to receive RF energy for generating plasma in the process chamber, and refining the baffle plate based on the first position. The baffle plate is to be arranged above a wafer in the process chamber to control plasma distribution on the wafer. The baffle plate has a shape of an annulus including a first annulus sector having a first inner radius and a second annulus sector having a second inner radius different from the second inner radius based on the refining.