CMP Temperature Control via Rate Quench
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chemical mechanical polishing (CMP) processes face challenges in achieving planarization of semiconductor substrates due to non-planar artifacts such as erosion and dishing, which are exacerbated by temperature variations and high friction during the polishing process.
Innovation Solution
Implementing a temperature control method that involves monitoring the polishing surface temperature and applying a rate quench process, such as a high flow high pressure deionized water rinse, to maintain a target temperature and reduce temperature variations, thereby minimizing erosion and dishing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high friction and temperature variations occur during CMP, then polishing pressure and speed can be increased to improve productivity, but erosion and dishing increase reducing manufacturing precision
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting polishing pressure and slurry flow rate based on real-time temperature monitoring. When temperature exceeds the target range, the system reduces pressure and increases slurry flow to cool the interface, thereby maintaining planarization quality while allowing higher productivity during normal operation.
Solution Approach 2:
The patent implements a feedback control system that continuously monitors temperature at the polishing interface and adjusts process parameters accordingly. Temperature sensors provide real-time data to a controller that modulates pressure and slurry flow to maintain optimal temperature conditions, preventing erosion and dishing while sustaining high productivity.
2Manufacturing precision
If polishing pressure is increased to improve planarization efficacy, then material removal rate increases, but temperature at the interface increases causing erosion
Solution Approach 1:
The patent uses slurry as an intermediary substance that serves multiple functions: it provides chemical etching action, acts as a coolant to manage interface temperature, and facilitates material removal. By optimizing slurry flow rate and composition, the system achieves effective planarization while controlling temperature-induced erosion.
Solution Approach 2:
The patent employs hydraulic principles by controlling slurry delivery through pressure-regulated flow systems. The slurry is delivered under controlled pressure to ensure adequate cooling and chemical action at the polishing interface, with flow rate dynamically adjusted based on temperature feedback to prevent excessive heating.
3Object-affected harmful factors
If relative speed between carrier head and polishing pad is increased to reduce erosion, then turbulence variations increase causing dishing
Solution Approach 1:
The patent applies dynamics by continuously adjusting the relative rotational speeds of the carrier head and polishing pad during the polishing process. The system modulates speed ratios to optimize the balance between reducing erosion through increased relative motion and minimizing turbulence-induced dishing, adapting conditions in real-time based on process monitoring.
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 improves planarization efficacy, reduces side effects like erosion and dishing, and maintains slurry component integrity, leading to better process stability and reduced defect performance.
Implementation Method 1
exposing the polishing surface to a rate quench process... such as a high flow high pressure deionized water rinse
Implementation Method 2
high flow high pressure deionized water rinse
Implementation Method 3
high friction during the polishing process
Data Source
AI summary
Methods for chemical mechanical polishing (CMP) of semiconductor substrates, and more particularly to temperature control during such chemical mechanical polishing are provided. In one aspect, the method comprises polishing the substrate with a polishing surface during a polishing process to remove a portion of the conductive material, repeatedly monitoring a temperature of the polishing surface during the polishing process, and exposing the polishing surface to a rate quench process in response to the monitored temperature so as to achieve a target value for the monitored temperature during the polishing process.