Chemical Planarization of Silicon Oxide Films Using Fluorine Adsorption
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Solution Overview
Problem
Chemical Mechanical Polishing (CMP) methods cause mechanical damage to surfaces during planarization of semiconductor devices due to the use of abrasive grains, which is undesirable.
Innovation Solution
A planarizing method involving a surface to be processed, such as a silicon oxide film, is brought into contact with a solid-state plate adsorbed with fluorine in an acidic processing solution, allowing chemical dissolution and planarization without mechanical polishing, using an ion exchanger like cerium or iron oxide to stabilize fluorine adsorption and facilitate a chemical reaction that dissolves the silicon oxide film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CMP method with abrasive grains is used for planarization, then planarization efficiency is improved, but mechanical damage occurs on the surface
Solution Approach 1:
The patent replaces the mechanical polishing action of CMP with a chemical dissolution mechanism. A solid-state plate with controlled solubility is brought into contact with the silicon oxide film in an aqueous environment, where chemical dissolution occurs at the contact interface. This substitution eliminates mechanical damage from abrasive grains while maintaining planarization capability through controlled chemical etching.
Solution Approach 2:
The solid-state plate acts as an intermediary medium between the silicon oxide film and the aqueous environment. The plate's controlled solubility allows it to dissolve slightly in water, creating a chemical reaction zone at the contact interface that planarizes the silicon oxide film without requiring direct mechanical contact with abrasive particles.
2Object-affected harmful factors
If chemical dissolution method is used instead of mechanical polishing, then mechanical damage is prevented, but planarization speed may decrease
Solution Approach 1:
The patent controls the planarization speed by adjusting parameters of the solid-state plate, including its composition, crystallinity, and solubility characteristics. By selecting materials with appropriate dissolution rates and controlling plate temperature, the chemical dissolution process achieves planarization speeds comparable to mechanical CMP while eliminating mechanical damage.
Solution Approach 2:
The planarization process uses periodic contact and separation between the solid-state plate and the silicon oxide film. The plate is repeatedly brought into contact with the film surface for dissolution, then separated to allow fresh aqueous solution to reach the contact zone, maintaining efficient chemical reaction rates throughout the planarization process.
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
This method effectively planarizes the silicon oxide film without mechanical damage, utilizing a chemical reaction to dissolve and smooth the surface, thereby preventing polishing damage and achieving efficient planarization.
Implementation Method 1
the surface to be processed of an object to be processed including a silicon oxide film is planarized in a processing solution by bringing the surface to be processed into contact with or close proximity with the surface of a solid-state plate on which fluorine is adsorbed
Implementation Method 2
a solid-state plate on which fluorine is adsorbed
Data Source
AI summary
According to one embodiment, a planarizing method is proposed. In the planarizing method, a surface to be processed of an object to be processed including a silicon oxide film is planarized in a processing solution by bringing the surface to be processed into contact with or close proximity with the surface of a solid-state plate on which fluorine is adsorbed. The bonding energy between fluorine and the solid-state plate is lower than that between fluorine and silicon.