Single-Platen CMP with Pad-in-a-Bottle Slurries for Back-End Polishing
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Solution Overview
Problem
Conventional three platen CMP processes for back-end applications are cumbersome, requiring multiple polishing pads and increasing costs due to frequent pad replacement and decreased device fabrication efficiency, as they necessitate multiple wafer transfers and extensive pad conditioning.
Innovation Solution
A single platen CMP process utilizing a single polishing pad with PIB type Cu bulk, Cu soft landing, and Cu barrier CMP slurries, which include micron-size polyurethane beads and specific additives, to achieve efficient polishing across multiple steps, reducing the need for multiple pads and enhancing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If three different platens are used for metal bulk, metal soft landing, and metal barrier CMP slurries, then polishing selectivity and removal rates are improved, but device fabrication efficiency decreases due to multiple wafer transfers
Solution Approach 1:
The patent merges three separate polishing operations (metal bulk, metal soft landing, and metal barrier CMP) that were previously performed on three different platens into a single platen system. This consolidation eliminates wafer transfers between platens while maintaining the sequential polishing steps on one integrated platform, thereby improving device fabrication efficiency without sacrificing polishing selectivity.
Solution Approach 2:
The single platen is designed to perform multiple polishing functions sequentially - handling metal bulk removal, metal soft landing, and metal barrier CMP operations. This multi-functional capability allows one platen to replace three specialized platens, eliminating transfer time while maintaining the distinct polishing characteristics required for each metal layer.
2Manufacturing precision
If three different platens with at least two different types of polishing pads are employed, then polishing performance for different metals is improved, but tool complexity and cost of ownership increase
Solution Approach 1:
The patent consolidates three separate platen systems with multiple polishing pads into a single platen system. This merging reduces the overall number of polishing pads required and simplifies the tool architecture while maintaining the capability to perform distinct polishing functions through sequential processing steps on the same platen.
Solution Approach 2:
The single platen is designed with universal capability to handle different metal types (copper, cobalt, tungsten) and perform multiple polishing functions (bulk removal, soft landing, barrier CMP) through controlled application of different slurries and parameters, eliminating the need for multiple specialized platens and reducing tool complexity.
3Manufacturing precision
If multiple polishing pads are used for different CMP slurries, then polishing selectivity is improved, but pad replacement frequency and cost increase
Solution Approach 1:
The patent reduces the number of polishing pads from multiple pads required for three different platens to a single polishing pad on one platen. This consolidation minimizes pad replacement frequency and associated downtime while maintaining polishing selectivity through the use of different CMP slurries and controlled processing parameters for each metal layer.
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 significantly reduces CMP processing times, increases semiconductor device fabrication efficiency, and lowers costs by minimizing pad replacement and tool downtime, while maintaining high selectivity and removal rates across different film types.
Implementation Method 1
abrasives, micron-size polyurethane (PU) beads having a size ranging from 2 to 100 μm
Implementation Method 2
PIB type advanced metal (such as Cu or Co) bulk, PIB type metal (such as Cu or Co) soft landing, and PIB type metal (such as Cu or Co) barrier Chemical Mechanical Planarization (CMP) slurries
Implementation Method 3
silicone-containing dispersing agent
Implementation Method 4
a chelating agent or dual chelating agents or tris chelating agents
Implementation Method 5
corrosion inhibitor
Implementation Method 6
an oxidizer added at the point of use
Data Source
AI summary
A single platen Chemical Mechanical Planarization (CMP) process using a novel pad-in-a-bottle (PIB) technology and PIB type CMP slurries for back-end CMP application is described to replace multiple (such as three) platens Chemical Mechanical Planarization (CMP) process for back-end CMP applications. The single platen with a single polishing pad is used for the whole back-end CMP process comprising metal bulk, metal soft landing, and metal barrier CMP.