Semiconductor Cleaning Composition for High Ti/W Selectivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dry etching methods for semiconductor substrates with titanium-titanium alloys result in damage to oxide films, particularly those with a relative dielectric constant of 60 or less, compromising the performance of the semiconductor substrate.
Innovation Solution
A semiconductor substrate cleaning composition comprising an oxidizing agent and a metal-tungsten corrosion inhibitor, without fluorine compounds, is used to etch titanium-titanium alloys with high selectivity, maintaining the integrity of oxide films by keeping the pH at 7 or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dry etching is used to etch titanium-titanium alloy with high Ti/W etching selectivity ratio, then etching selectivity is improved, but oxide film is damaged
Solution Approach 1:
The invention changes the chemical parameters of the etching composition by specifying precise pH ranges (0.5-3.0) and controlled concentrations of oxidizing agents (0.01-5% by mass) and fluorine compounds (0.001-0.005% by mass). This parameter optimization enables high Ti/W etching selectivity ratio while minimizing damage to oxide films with relative dielectric constant of 60 or less, resolving the contradiction between etching effectiveness and film protection.
2Productivity
If fluorine compound is used to enhance etching capability, then etching rate is improved, but oxide film damage increases
Solution Approach 1:
The invention precisely controls the fluorine compound concentration at 0.001-0.005% by mass, which is sufficiently low to protect oxide films yet high enough to maintain effective etching capability. This delicate parameter balance resolves the contradiction between achieving adequate etching rate and preventing oxide film damage.
Solution Approach 2:
The etching composition uses a composite formulation combining multiple components: oxidizing agents (0.01-5% by mass), fluorine compounds (0.001-0.005% by mass), and pH adjusters to achieve pH 0.5-3.0. This composite approach allows the system to achieve high etching selectivity for titanium-titanium alloy while the controlled fluorine content protects oxide films from excessive damage.
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 composition achieves high Ti/W etching selectivity while minimizing damage to oxide films, ensuring the semiconductor substrate maintains desired performance.
Implementation Method 1
A semiconductor substrate cleaning composition including: (A) an oxidizing agent; and (B) a metal-tungsten corrosion inhibitor
Implementation Method 2
supplying a hydrogen-containing gas to embrittle titanium nitride or the like in advance
Data Source
Figure 1~3
AI summary
Provided is a semiconductor substrate cleaning composition capable of reducing damage to an oxide film while having a high Ti/W etching selectivity ratio. Disclosed is a semiconductor substrate cleaning composition including: (A) an oxidizing agent; and (B) a metal-tungsten corrosion inhibitor, wherein the semiconductor substrate cleaning composition does not include (C) a fluorine compound or further contains the fluorine compound in an amount of less than 0.005% by mass with respect to a total mass of the semiconductor substrate cleaning composition, and the semiconductor substrate cleaning composition has a pH of 7 or less.