CMP Slurry With Temperature-Sensitive Oxidizer for Tungsten Flatness
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Solution Overview
Problem
Current chemical mechanical polishing processes for semiconductor devices face challenges in achieving optimal flatness and reducing polishing time for metal layers, particularly tungsten layers, due to inadequate control over etch and removal rates during the chemical mechanical polishing process.
Innovation Solution
A chemical mechanical polishing slurry comprising deionized water, abrasive particles, and a temperature-sensitive oxidizing agent, such as Sodium Persulfate, is used to control the static etch and removal rates of metal layers within a temperature range of 10° C. to 75° C., alongside a pH adjusting agent and catalyst, to enhance polishing efficiency and flatness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional chemical mechanical polishing slurry is used, then polishing process can be performed, but flatness of metal layer is insufficient and polishing time is excessive
Solution Approach 1:
The patent uses a temperature-sensitive oxidizing agent that changes its oxidizing activity based on temperature. At lower temperatures (10-25°C), the oxidizing agent maintains low static etch rate for high flatness. At higher temperatures (60-75°C), the oxidizing agent increases oxidizing activity to enhance removal rate, thereby reducing polishing time. This dynamic parameter change resolves the contradiction between flatness and polishing time.
Solution Approach 2:
The polishing slurry system dynamically adjusts its chemical activity through temperature-dependent oxidizing agent behavior. The system transitions from a static etching regime at low temperature to a dynamic removal regime at high temperature, allowing optimization of both flatness and polishing time through controlled temperature variation during the polishing process.
2Productivity
If temperature is increased to improve removal rate, then polishing time is reduced, but static etch rate increases causing poor flatness
Solution Approach 1:
The temperature-sensitive oxidizing agent exhibits parameter changes in its oxidizing activity with temperature. At elevated temperatures, the oxidizing agent becomes more active, increasing removal rate for higher productivity. However, the patent controls the concentration and type of oxidizing agent to ensure that static etch rate increase is manageable, maintaining flatness even at higher temperatures during active polishing.
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 slurry effectively shortens polishing time and improves the planarity of metal layers by maintaining controlled etch and removal rates across varying temperatures, thereby improving the manufacturing efficiency of semiconductor devices.
Implementation Method 1
an aqueous solution including a temperature-sensitive oxidizing agent. The temperature-sensitive oxidizing agent may be configured to control both a static etch rate of a metal layer and a removal rate of the metal layer in a chemical mechanical polishing process
Implementation Method 2
an aqueous solution including a catalyst
Data Source
AI summary
Provided is a chemical mechanical polishing slurry used for chemical mechanical polishing of a metal layer. The chemical mechanical polishing slurry may include deionized water, abrasive particles, and an aqueous solution including a temperature-sensitive oxidizing agent configured to control both the static etch rate and removal rate of the metal layer in a chemical mechanical polishing process when the polishing temperature of the chemical mechanical polishing process is 10° C. to 75° C.