Polishing Composition for Through-Silicon Via Structures
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Solution Overview
Problem
Polishing semiconductor substrates with through-silicon via structures is challenging due to the difference in polishing speed and surface accuracy between silicon and copper or copper alloys, and existing methods fail to maintain a suitable polishing speed for silicon while preventing contamination of silicon with copper.
Innovation Solution
A polishing composition containing an oxidizing agent with a standard electrode potential of 350 to 740 mV, a silicon polishing accelerating agent, a through-silicon via material polishing speed increasing agent, and a silicon contamination preventing agent, along with water, is used to maintain the polishing speed of silicon while controlling the polishing speed of copper or copper alloys and preventing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If organic alkaline compounds and strong oxidizing agents are used to increase polishing speed for both silicon and copper, then polishing speed is improved, but contamination of silicon with copper occurs
Solution Approach 1:
The patent introduces complexing agents as intermediary substances that selectively bind to copper ions released during polishing. These complexing agents form stable copper-complexes that prevent copper deposition on silicon surfaces, acting as mediators between the oxidizing agent and the substrate materials
Solution Approach 2:
The patent converts the harmful effect of copper ion release during polishing into a beneficial outcome by using complexing agents to capture these copper ions. The copper ions that would otherwise contaminate silicon are instead sequestered by complexing agents, transforming a pollution problem into a controlled chemical process
2Ease of manufacture
If conventional polishing compositions are used to polish through-silicon via structures, then polishing process is simple, but suitable polishing speed and surface accuracy cannot be achieved simultaneously
Solution Approach 1:
The patent creates a composite polishing composition containing multiple functional components: oxidizing agents (sodium chlorite/potassium bromate), organic alkaline compounds (specific amines), and complexing agents. This composite formulation achieves both high polishing speed and excellent surface accuracy with controlled differential polishing rates, maintaining practical simplicity while delivering superior results
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 solution effectively maintains a high polishing speed for silicon and copper or copper alloys, preventing contamination of silicon with copper, and achieving a suitable surface accuracy, which was not achievable with conventional methods.
Implementation Method 1
an oxidizing agent having a standard electrode potential of 350 to 740 mV
Implementation Method 2
standard electrode potential
Implementation Method 3
a silicon polishing accelerating agent
Implementation Method 4
a through-silicon via material polishing speed increasing agent
Implementation Method 5
a silicon contamination preventing agent
Data Source
AI summary
Provided is a polishing composition used for polishing a semiconductor substrate having a through-silicon via structure, comprising an oxidizing agent having a standard electrode potential of 350 mV or more and 740 mV or less, a silicon polishing accelerating agent, a through-silicon via material polishing speed increasing agent, a silicon contamination preventing agent, and water.