Semiconductor Etchant Composition for Selective Si Removal from SiGe
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Solution Overview
Problem
Existing etching solutions for semiconductor manufacturing, such as those described in JP2019-050364A, are inadequate for selectively removing silicon (Si) from silicon germanium (SiGe) substrates, as they lack sufficient selectivity and efficiency.
Innovation Solution
A treatment liquid comprising a nitrogen-containing polymer, quaternary ammonium hydroxide, an organic solvent with an SP value of 25 MPa1/2 or more, and water, with specific compositions and pH levels, is used to selectively etch Si from SiGe substrates, suppressing SiGe etching while enhancing Si removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etchants (water, quaternary ammonium compound, amine compound, water-miscible solvent) are used, then the etching process can be performed, but the ability to selectively remove Si with respect to SiGe is insufficient
Solution Approach 1:
The patent changes the chemical parameters of the etchant by introducing a specific nitrogen-containing polymer with controlled molecular weight (1,000-10,000) and nitrogen content (10-40%), along with specific quaternary ammonium hydroxide compounds. These parameter changes enable the etchant to selectively remove Si while suppressing SiGe etching, achieving the required selectivity for semiconductor manufacturing
Solution Approach 2:
The patent creates a composite etching system by combining multiple components: nitrogen-containing polymer, quaternary ammonium hydroxide, water-miscible solvent, and water. This composite formulation synergistically enhances Si selective removability while controlling SiGe corrosion, resolving the contradiction between selective removal ability and etching reliability
2Productivity
If polyethyleneimine is used as surfactant to improve etching ability, then etching can be enhanced, but the selective removal ability of Si with respect to SiGe remains insufficient
Solution Approach 1:
The patent modifies the polymer component by specifying nitrogen-containing polymers with molecular weights of 1,000-10,000 and nitrogen content of 10-40%, which are more effective than conventional polyethyleneimine. This parameter optimization simultaneously improves etching efficiency and Si selective removability, eliminating the contradiction between productivity and manufacturing precision
3Productivity
If stronger etching power is used to remove Si faster, then productivity increases, but SiGe corrosion increases and selectivity decreases
Solution Approach 1:
The nitrogen-containing polymer acts as an intermediary that modifies the etching mechanism. It enables rapid Si removal through enhanced chemical interaction while simultaneously suppressing SiGe corrosion by forming protective complexes or altering the etching pathway, thus resolving the contradiction between productivity and harmful effects
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 achieves selective removal of Si from SiGe substrates, improving the etching process by enhancing Si selective removability and reducing SiGe corrosion, thereby improving semiconductor manufacturing efficiency.
Implementation Method 1
it is general to perform an etching process using a chemical liquid... an etchant contains water, at least one of a quaternary ammonium compound or an amine compound
Implementation Method 2
an organic solvent having an SP value of 25 MPa1/2 or more... the treatment liquid is used for an object to be treated containing silicon germanium and silicon
Data Source
AI summary
An object of the present invention is to provide a treatment liquid for producing a semiconductor, which is capable of selectively removing Si in a case of being applied to an object to be treated containing SiGe and Si. The treatment liquid for manufacturing a semiconductor according to the present invention includes: a nitrogen-containing polymer; a quaternary ammonium hydroxide; an organic solvent having an SP value of 25 MPa1/2 or more; and water. Polyalkyleneimine is excluded from the nitrogen-containing polymer.