CMP Polishing Head Laser Heating for Wafer Temperature Uniformity
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Solution Overview
Problem
Existing chemical mechanical polishing (CMP) technologies face issues with in-plane uniformity of polishing rates due to inadequate temperature control, slow temperature rise, and changes in polishing characteristics from slurry inhibition and concentration fluctuations.
Innovation Solution
A semiconductor manufacturing apparatus with laser irradiation parts on a polishing head to heat the wafer surface, combined with a cooling mechanism to separately control heating and cooling, ensuring uniform temperature distribution and rapid temperature adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heat exchange methods are used to control temperature, then temperature can be controlled, but temperature cannot be raised rapidly and in-plane uniformity deteriorates
Solution Approach 1:
The patent replaces the mechanical heat exchange system with a laser irradiation system. The laser beam directly irradiates the polishing pad to generate heat, eliminating the need for thermal conduction through heat exchangers. This substitution enables rapid temperature rise and precise spatial control of temperature distribution, directly resolving the contradiction between temperature control capability and temperature rise speed.
2Temperature
If heat exchanger is installed on polishing pad, then temperature control is achieved, but in-plane uniformity of polishing rate deteriorates
Solution Approach 1:
The patent applies local quality by using laser irradiation to create specific temperature distribution patterns on the polishing pad. The laser can be focused on specific regions to achieve localized heating, allowing different areas of the polishing pad to have different temperatures optimized for their respective polishing zones. This precise spatial control improves in-plane uniformity of polishing rate while maintaining temperature control.
3Productivity
If slurry is put onto polishing table with polishing pad, then polishing is performed, but polishing characteristics change due to slurry inflow inhibition and concentration decrease
Solution Approach 1:
The patent replaces the mechanical slurry delivery system with a laser-induced thermal field. By heating the polishing pad locally, the laser promotes chemical reactions between the slurry and workpiece surface, enhancing polishing effectiveness without relying on high slurry concentration or continuous slurry flow. This substitution maintains polishing performance while preventing slurry depletion.
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 in-plane uniformity of polishing characteristics by promoting chemical reactions and preventing local temperature differences, enhancing polishing rate homogeneity and eliminating step differences.
Implementation Method 1
a plurality of laser irradiation parts on the polishing head, at least one of the plurality of laser irradiation parts being a laser irradiation part configured to radiate a laser beam toward a back surface of the polishing object
Data Source
AI summary
A semiconductor manufacturing apparatus is a semiconductor manufacturing apparatus for holding a polishing object on a polishing head and polishing a surface of the polishing object. The semiconductor manufacturing apparatus includes a plurality of laser irradiation parts on the polishing head. At least one of the laser irradiation parts is a laser irradiation part configured to radiate a laser beam toward the back surface side of the polishing object.