Capacitor Electrode Lamination for Faster SiN Deposition Coverage
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Solution Overview
Problem
The deposition speed of SiN thin-films in capacitor electrodes is low, leading to low step coverage and degradation of capacitor characteristics, and increasing the thickness of electrodes to improve coverage requires excessive time, reducing the space for the dielectric layer and decreasing its dielectric constant.
Innovation Solution
Consecutively perform the formation of TiN and SiN thin-films multiple times, using sources containing titanium and silicon with nitrogen reactants, and adjust the ratio of TiN to SiN formation cycles to improve deposition speed and coverage, employing sources like hexachlorodisilane (Si2Cl6) or dichlorosilane (SiH2Cl2) for SiN formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the thickness of each electrode is increased to improve step coverage, then step coverage is improved, but deposition time increases excessively
Solution Approach 1:
The patent changes the deposition parameters by alternating between TiN and SiN thin-film formation with optimized thickness ratios (T1:T2 = 1:1 to 4:1). This parameter change enables achieving sufficient step coverage while reducing total deposition time compared to forming thick electrodes with a single material layer.
Solution Approach 2:
The patent uses composite electrode structures combining TiN and SiN thin-films. By laminating different materials with complementary properties, the electrode achieves both adequate step coverage and reduced deposition time, as each material contributes differently to the overall performance.
2Manufacturing precision
If deposition time is increased to achieve target electrode thickness, then electrode thickness is sufficient, but space for dielectric layer decreases and dielectric constant decreases
Solution Approach 1:
The patent optimizes the deposition parameters by controlling the ratio of TiN to SiN thin-film formation cycles (T1:T2 = 1:1 to 4:1) and adjusting individual layer thicknesses. This enables achieving the required electrode thickness within reduced time, preserving sufficient space for the dielectric layer and maintaining its dielectric constant.
Solution Approach 2:
The patent employs periodic alternation between forming TiN thin-films and SiN thin-films. This periodic deposition process allows efficient use of deposition time while achieving the target electrode thickness, preventing excessive time consumption that would otherwise reduce dielectric layer space.
3Ease of manufacture
If SiH4 is used as source for SiN thin-film formation, then deposition process is simple, but deposition speed is low
Solution Approach 1:
The patent changes the source material parameters by using silicon precursors containing chlorine (such as hexachlorodisilane or dichlorosilane) instead of SiH4. This parameter change significantly increases deposition speed while maintaining process feasibility, resolving the contradiction between simplicity and productivity.
Solution Approach 2:
The patent employs a multi-functional deposition approach where the same CVD process can form both TiN and SiN thin-films by alternating source materials. This maintains process simplicity while achieving high deposition speeds through optimized source selection for each material layer.
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
Enhances the deposition speed of SiN thin-films, reduces the time needed to achieve target thickness, and improves step coverage, ensuring uniform thickness distribution on substrates with trenches, thereby maintaining dielectric layer integrity.
Implementation Method 1
forming a TiN thin-film by injecting a source containing titanium (Ti) and a reactant containing nitrogen; and forming a SiN thin-film by injecting a source containing silicon (Si) and a reactant containing nitrogen
Data Source
AI summary
A method for forming a capacitor electrode in accordance with an exemplary embodiment includes a step of forming a TiN thin-film by injecting a source containing titanium (Ti) and a reactant containing nitrogen and a step of forming SiN thin-film by injecting a source containing silicon (Si) and a reactant containing nitrogen, and at least one of the source containing titanium (Ti) and the source containing silicon (Si) is injected a plurality of times.Thus, in accordance with exemplary embodiments, when at least one of a lower electrode and an upper electrode of a capacitor is formed by laminating the TiN thin-film and the SiN thin-film, a deposition speed of the SiN thin film may be improved, and step coverage of the thin film may be improved.