Single-Phase Multi-Element PEALD Film Formation
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Solution Overview
Problem
Existing methods for depositing multi-element Si-based insulation films using atomic layer deposition (ALD) require laminating different sub-layers, which are complex and prone to plasma damage, leading to insufficient etch selectivity and deformation of substrates.
Innovation Solution
A method for forming a single-phase multi-element film by plasma enhanced atomic layer deposition (PEALD) using a single deposition cycle, where a precursor is adsorbed and decomposed by an inert gas plasma, then reacted with a reactant gas plasma, incorporating silicon and multiple non-metal elements without continuous reactant gas supply, to create a uniform and dense film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a multi-element Si-based insulation film is deposited by ALD using a laminate method with different sub-layers, then the film composition can be controlled, but the process complexity increases and more steps are required
Solution Approach 1:
The patent combines multiple element incorporation steps into a single deposition cycle. By using a multi-element precursor that contains silicon and at least two non-metal elements, along with a reactant gas containing another non-metal element, the method deposits a single-phase multi-element film (SiOCN, SiCOB, or SiON) in one cycle rather than requiring separate sub-layers for each element combination.
Solution Approach 2:
The deposition cycle is designed to be universal for creating different multi-element film compositions. The same basic cycle structure (precursor adsorption, inert gas plasma decomposition, reactant gas plasma reaction) can produce various film types (SiOC, SiON, SiOCN, SiCOB) by changing the precursor and reactant gas selection, eliminating the need for different deposition cycles for different sub-layers.
2Ease of manufacture
If a mono-element Si-based insulation film is deposited by ALD, then the deposition process is simple, but the etch selectivity is insufficient and plasma damage occurs
Solution Approach 1:
The patent employs composite multi-element materials (SiOC, SiON, SiOCN, SiCOB) that combine silicon with multiple non-metal elements. These composite films inherently provide better etch selectivity and reduced plasma damage compared to mono-element films, while maintaining a relatively simple single-cycle deposition process. The composite nature of the film provides both the simplicity of a unified deposition process and the reliability of enhanced etch selectivity.
3Stability of the object's composition
If a multi-element Si-based insulation film is deposited by ALD using a laminate method, then the film can be formed, but substrate deformation occurs due to plasma damage
Solution Approach 1:
By merging all element incorporation into a single deposition cycle using a multi-element precursor, the total plasma exposure time is reduced compared to the laminate method which requires multiple separate deposition cycles. The single-cycle approach minimizes cumulative plasma damage to the substrate while still achieving the desired multi-element film composition.
Solution Approach 2:
The method incorporates all necessary elements into the film structure during a single preliminary deposition cycle, rather than requiring subsequent additional cycles to add different sub-layers. This preliminary action of incorporating multiple elements simultaneously prevents the need for repeated plasma exposure that would otherwise cause cumulative substrate damage.
4Device complexity
If a single-phase multi-element film is deposited by PEALD using a single deposition cycle, then the process is simplified, but the film uniformity and density must be maintained
Solution Approach 1:
The patent carefully controls deposition parameters including precursor pulse duration (0.1-10 seconds), reactant gas pulse duration (0.1-10 seconds), pressure (10-1000 mTorr), and temperature (25-400°C) to optimize film quality. By adjusting these parameters within specific ranges, the method maintains high film uniformity and density while using a simplified single-cycle process. The parameter optimization ensures that the single-cycle approach does not compromise manufacturing precision.
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 allows for the deposition of highly uniform multi-element Si-based films with improved etch selectivity and reduced substrate damage, eliminating the need for laminating different sub-layers and simplifying the process.
Implementation Method 1
decomposing the precursor adsorbed on the substrate by an inert gas plasma
Implementation Method 2
reacting the decomposed precursor with a reactant gas plasma in the presence of the inert gas plasma
Implementation Method 3
adsorbing a precursor on the substrate in the absence of reactant and plasma
Data Source
AI summary
A method for forming a single-phase multi-element film on a substrate in a reaction zone by PEALD repeating a single deposition cycle. The single deposition cycle includes: adsorbing a precursor on the substrate in the absence of reactant and plasma; decomposing the precursor adsorbed on the substrate by an inert gas plasma; and reacting the decomposed precursor with a reactant gas plasma in the presence of the inert gas plasma. The multi-element film contains silicon and at least two non-metal elements constituting a matrix of the film, the precursor contains silicon and optionally at least one non-metal element to be incorporated in the matrix, and the reactant gas contains at least one non-metal element to be incorporated in the matrix.