BPSG Resist Underlayer Film for Clean Residue Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, the existing patterning processes using silicon-containing resist under layer films face challenges in removing residues without damaging the substrate, as the films are difficult to distinguish from the substrate materials, leading to reduced yield and processing issues.
Innovation Solution
A patterning process utilizing a BPSG film as the resist under layer, formed with a specific composition including a base polymer and an organic compound with hydroxyl or carboxyl groups, allowing for easy removal by wet etching with an ammonia aqueous solution containing hydrogen peroxide, while maintaining substrate integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a silicon-containing resist under layer film is used in patterning, then pattern transfer capability is improved, but residue removal becomes difficult without damaging the substrate
Solution Approach 1:
The patent applies composite materials by creating a BPSG film that combines boron, phosphorus, and silicon elements in specific proportions (SiO2: 60-80 wt%, B2O3: 5-20 wt%, P2O5: 5-20 wt%). This composite composition provides both the pattern transfer capability of silicon-containing films and the wet etchability of boron-phosphorus modified glass, resolving the contradiction between pattern transfer performance and residue removal ease.
Solution Approach 2:
The patent changes the chemical composition parameters of the resist under layer film by incorporating specific amounts of boron and phosphorus oxides alongside silicon dioxide. The film contains 1-10 at% boron and 1-10 at% phosphorus, which modifies the etching characteristics to enable selective removal by ammonia-based solutions while maintaining the underlying silicon substrate integrity.
2Stability of the object's composition
If the resist under layer film composition is made similar to substrate material, then adhesion is improved, but selective removal becomes impossible
Solution Approach 1:
The patent applies local quality by creating a compositional gradient within the BPSG film. The film maintains silicon content (20-40 at%) for adhesion to the silicon substrate while incorporating boron (1-10 at%) and phosphorus (1-10 at%) at controlled concentrations that provide selective wet etchability. This local compositional differentiation enables both strong adhesion and selective removal.
Solution Approach 2:
The BPSG film acts as an intermediary layer between the silicon substrate and the photoresist. It provides the adhesion function of silicon-containing materials while its modified glass composition (with boron and phosphorus) enables selective removal by ammonia-based solutions, thus mediating between the conflicting requirements of adhesion and selective removal.
3Strength
If conventional silicon-containing films are used, then etching resistance is maintained, but residue cleanup requires harsh chemicals that damage the substrate
Solution Approach 1:
The patent converts the traditionally harmful characteristic of silicon-containing films (difficulty in removal) into a benefit by modifying the composition to enable selective wet etching. The boron-phosphorus-silicon glass film provides etching resistance during patterning but can be selectively removed by ammonia-based solutions, eliminating the need for harsh chemicals that damage the substrate.
Solution Approach 2:
The patent replaces the mechanical/chemical etching process with a wet chemical etching process using ammonia-based solutions. Instead of using harsh chemicals or prolonged etching to remove residues, the modified BPSG film enables gentle selective removal through wet chemistry, substituting a damaging removal mechanism with a benign one.
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
Enables the formation of fine mask patterns on substrates with clean residue removal, improving device production yield by preventing substrate damage and ensuring effective pattern transfer without size conversion.
Implementation Method 1
removing a residue of the BPSG film remaining on the under layer film having the formed pattern by wet etching using an ammonia aqueous solution containing hydrogen peroxide
Data Source
AI summary
The present invention provides a patterning process, which comprises step of forming a BPSG film on the under layer film by using a composition for forming a coating type BPSG film including a base polymer and an organic compound with a content of 25 parts by mass or more of the organic compound with respect to 100 parts by mass of the base polymer, the base polymer having a silicon containing unit, a boron containing unit and a phosphorus containing unit with a total content of the boron containing unit and the phosphorus containing unit being 10 mol % or more, the organic compound having two or more hydroxyl groups or carboxyl groups per one molecule. There can be provided a patterning process in which a fine mask pattern can be formed on the substrate to be processed by the multilayer resist method, and the residue of the resist under layer film on the mask pattern can be removed cleanly enough to process the substrate to be processed without causing damage to the substrate to be processed and the under layer film.