Specimen Fabrication Using Fluorocarbon Etchant
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for observing semiconductor device structures face challenges in achieving sufficient image resolution due to insufficient contrast differences, particularly when using focused ion beam (FIB) processing, which can cause damage and alter the original structure, and existing etch-assisting gases are not effectively adsorbed by the sample surface.
Innovation Solution
A specimen fabricating apparatus and method utilizing a charged particle beam optical system with an etchant material containing fluorine and carbon, solid or liquid at standard conditions, and lacking oxygen, to create a difference in sputter rates between materials like Si and SiO2, allowing for effective decoration of the specimen profile with minimal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If FIB is irradiated obliquely to form irregularities by physical sputtering, then contrast difference is improved, but processing damage increases
Solution Approach 1:
The patent changes the chemical composition parameters of the etchant material from conventional halogenated gases to a material containing fluorine and carbon but no oxygen, in solid or liquid state at standard conditions. This parameter change enables effective section decoration with reduced processing damage by utilizing chemical reactions that are more selective and less damaging to the specimen structure.
Solution Approach 2:
The patent utilizes phase transition by employing an etchant material that is solid or liquid at standard conditions (1 barometric pressure and 25°C) rather than gaseous. This phase difference allows the material to be effectively adsorbed by the sample surface and provides better control over the etching process, reducing processing damage while maintaining image resolution.
2Manufacturing precision
If etch-assisting gases are used to form irregularities, then sputtering rate difference is improved, but adsorption efficiency decreases
Solution Approach 1:
The patent changes the physical state parameter of the etchant material from gaseous to solid or liquid at standard conditions. This parameter change dramatically improves adsorption efficiency because solid or liquid materials can be more effectively adsorbed by the sample surface compared to gases. The material contains fluorine and carbon in molecules and no oxygen, providing both high adsorption efficiency and effective sputtering rate differentiation.
Solution Approach 2:
The patent employs a composite etchant material containing both fluorine and carbon elements in molecular structure, with no oxygen. This composite composition provides dual functionality: fluorine contributes to high sputtering rate difference between materials like Si and SiO2, while the solid or liquid state ensures effective adsorption by the sample surface, resolving the contradiction between sputtering efficiency and adsorption efficiency.
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 approach enables high-accuracy, high-contrast SEM observation of semiconductor device sections with reduced processing damage, improving failure analysis efficiency and semiconductor process yield.
Implementation Method 1
Focused ion beam (referred below to as FIB) 201 is used to process a rectangular hole 202
Implementation Method 2
a difference in processing sputtering yield, attributable to a material, is made use of
Implementation Method 3
the number of secondary electrons (or reflected electrons) generated from the position to thereby form an image to be observed
Data Source
AI summary
A specimen fabricating apparatus comprises: a specimen stage, on which a specimen is placed; a charged particle beam optical system to irradiate a charged particle beam on the specimen; an etchant material supplying source to supply an etchant material, which contains fluorine and carbon in molecules thereof, does not contain oxygen in molecules thereof, and is solid or liquid in a standard state; and a vacuum chamber to house therein the specimen stage. A specimen fabricating method comprises the steps of: processing a hole in the vicinity of a requested region of a specimen by means of irradiation of a charged particle beam; exposing the requested region by means of irradiation of the charged particle beam; supplying an etchant material, which contains fluorine and carbon in molecules thereof, does not contain oxygen in molecules thereof, and is solid or liquid in a standard state, to the requested region as exposed; and irradiating the charged particle beam on the requested region as exposed.