Selective Silicon Nitride Film Deposition via Chlorine Radical Blocking
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Solution Overview
Problem
Existing methods fail to selectively deposit silicon nitride films on flat surfaces between minute recesses on substrates, often resulting in films forming on recess surfaces due to incomplete adsorption blocking.
Innovation Solution
A film deposition method and apparatus that utilize a chlorine radical adsorbing step to create an adsorption blocking area on flat surfaces, followed by a nitriding step to form silicon adsorption sites, and a raw gas adsorbing step to deposit silicon nitride films exclusively on flat surfaces, while preventing adsorption in recesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional film deposition method is used, then film deposition occurs on all surfaces including minute recesses, but selective deposition on flat surfaces between recesses cannot be achieved
Solution Approach 1:
The invention applies preliminary action by performing a chlorine radical adsorbing step before the main film deposition process. This preliminary step creates an adsorption blocking area on the flat surfaces between minute recesses, preventing subsequent raw gas adsorption in those regions. By preparing the substrate surface in advance with chlorine radical adsorption, the method achieves selective deposition only on the minute recesses while excluding the flat surfaces, thereby resolving the technical contradiction between deposition selectivity and process complexity.
2Manufacturing precision
If the adsorption blocking area is not sufficiently formed, then film deposition occurs on both flat surfaces and recess surfaces, but film uniformity on flat surfaces cannot be ensured
Solution Approach 1:
The invention applies parameter changes by systematically adjusting the chlorine radical adsorption conditions, including controlling the chlorine containing gas flow rate, activation power, and adsorption time. By optimizing these parameters, the method achieves sufficient chlorine radical adsorption on flat surfaces to create an effective adsorption blocking area, ensuring that subsequent film deposition occurs uniformly only on the minute recesses. This parameter optimization resolves the contradiction between achieving sufficient adsorption blocking and maintaining film uniformity.
3Manufacturing precision
If the nitriding step is performed with high N* activated species density, then bottom-up growth occurs in minute recesses, but conformal growth control becomes difficult
Solution Approach 1:
The invention applies periodic action by dividing the film deposition process into distinct sequential steps: first performing a nitriding step with high N* activated species density to achieve bottom-up growth in minute recesses, then switching to a condition with lower N* density for conformal growth control. This periodic switching between different activation conditions allows the method to first fill the minute recesses from the bottom up, then subsequently grow conformal films on the flat surfaces, thereby resolving the contradiction between achieving bottom-up growth and maintaining conformal growth control.
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 method allows for the selective deposition of silicon nitride films on flat surfaces between minute recesses, ensuring uniformity and preventing film formation in recesses, thereby enhancing the precision and control of film deposition.
Implementation Method 1
a chlorine radical adsorbing step of supplying a chlorine containing gas that is activated onto a front surface of the substrate to cause the chlorine radical to be adsorbed entirely on the front surface of the substrate
Implementation Method 2
a nitriding step of supplying a nitriding gas that is activated onto the substrate on which the chlorine radical adsorbs, causing the chlorine radical adsorbing on the flat surface, and nitride the flat surface from among the front surface of the substrate so as to form a silicon adsorption site
Implementation Method 3
a raw gas adsorbing step of supplying a raw gas that contains silicon and chlorine onto the substrate so as to cause the raw gas to adsorb onto the silicon adsorption site
Data Source
AI summary
A film deposition method for depositing a silicon nitride film of selectively depositing on a flat surface of a substrate between minute recesses including a chlorine radical adsorbing step of supplying a chlorine containing gas that is activated onto a front surface of the substrate to cause the chlorine radical to be adsorbed entirely on the front surface of the substrate, a nitriding step of supplying a nitriding gas that is activated onto the substrate on which the chlorine radical adsorbs, causing the chlorine radical adsorbing on the flat surface, and nitride the flat surface from among the front surface of the substrate so as to form a silicon adsorption site, and a raw gas adsorbing step of supplying a raw gas that contains silicon and chlorine onto the substrate so as to cause the raw gas to adsorb onto the silicon adsorption site.