TiN Treatment Liquid for Selective Dissolution Over Tungsten
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Solution Overview
Problem
Existing treatment liquids for removing titanium nitride (TiN) from semiconductor substrates have insufficient dissolution rates and ratios compared to tungsten (W), hindering efficient and selective removal processes.
Innovation Solution
A treatment liquid comprising water, a cationic compound, an anionic compound selected from resins with specific functional groups, and an oxidizing agent, with a pH of 7.0 or less and no abrasive grains, is developed to enhance the dissolution rate and selectivity of TiN over W.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If existing treatment liquid compositions are used, then tungsten dissolution is controlled, but titanium nitride dissolution rate is insufficient
Solution Approach 1:
The patent changes the chemical parameters of the treatment liquid by introducing a cationic compound with specific functional groups (amino, imino, or biguanide groups) and controlling the pH to be 7.0 or less. This parameter change enables simultaneous improvement of TiN dissolution rate and selectivity ratio, resolving the technical contradiction between quantity of substance and reliability.
2Productivity
If oxidizing agents and etchants are used to increase TiN dissolution, then TiN dissolution rate improves, but selectivity ratio deteriorates
Solution Approach 1:
The cationic compound acts as an intermediary that mediates between the oxidizing/etching action and the TiN/TiN interface. It provides selective chemical interaction that enhances TiN dissolution while protecting tungsten, thus improving both productivity and manufacturing precision simultaneously.
Solution Approach 2:
The patent utilizes strong oxidizing agents in combination with the cationic compound to accelerate TiN dissolution. The cationic compound enhances the oxidizing effect specifically on TiN while maintaining selectivity, resolving the contradiction between dissolution efficiency and selective removal accuracy.
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 treatment liquid achieves a higher dissolution rate and selectivity for TiN, ensuring efficient removal while minimizing W dissolution, thus improving the semiconductor manufacturing process.
Implementation Method 1
an oxidizing agent
Implementation Method 2
a cationic compound; an anionic compound selected from the group consisting of a resin having a carboxy group or a salt thereof, a resin having a sulfo group or a salt thereof, a resin having a phosphorous acid group or a salt thereof, and a resin having a phosphoric acid group or a salt thereof
Data Source
AI summary
A treatment liquid is a treatment liquid including water; a cationic compound; an anionic compound selected from the group consisting of a resin having a carboxy group or a salt thereof, a resin having a sulfo group or a salt thereof, a resin having a phosphorous acid group or a salt thereof, and a resin having a phosphoric acid group or a salt thereof; and an oxidizing agent, in which the treatment liquid has a pH of 7.0 or less, and the treatment liquid is substantially free of abrasive grains.