Film Layer Deposition with Plasma Pretreatment for Better Step Coverage
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Solution Overview
Problem
In semiconductor film layer deposition processes, the deposition rate and step coverage rate are typically low, leading to poor film layer quality due to the formation of defective layers and native oxide layers, which can result in scrapped wafers and reduced product yield.
Innovation Solution
A method involving pulsed etching to remove defective layers, substrate surface treatment to eliminate native oxide layers, and a pretreatment step to form attachment points on the substrate, followed by plasma deposition using the same reaction source gas, enhancing deposition rate and step coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition process is used, then deposition efficiency is maintained, but film layer quality deteriorates due to defective layers and native oxide layers
Solution Approach 1:
The patent applies preliminary action by performing substrate treatment before deposition to remove native oxide layers and defective layers. The substrate is treated with oxygen plasma or chemical solutions (such as HF, NH4HF2, or NH4OH) prior to film deposition, ensuring a clean surface that prevents defect formation during deposition, thereby improving film layer quality without sacrificing deposition efficiency
Solution Approach 2:
The patent employs parameter changes by optimizing deposition parameters including temperature (400-650°C), pressure (1-20 Torr), and gas flow rates. By adjusting these parameters and using different reaction source gases (such as titanium tetrachloride, titanium isopropoxide, or ammonia), the process achieves both high deposition efficiency and superior film layer quality
2Productivity
If deposition rate is increased, then productivity improves, but step coverage rate deteriorates
Solution Approach 1:
The patent applies periodic action by using pulsed deposition processes where the deposition is performed in cycles with controlled gas flow patterns. The reaction source gas is introduced in pulses rather than continuously, allowing for better gas distribution and plasma uniformity across the substrate surface, which improves step coverage while maintaining overall deposition rate
Solution Approach 2:
The patent employs local quality by optimizing deposition conditions for different regions of the substrate. By controlling gas flow distribution, plasma uniformity, and substrate temperature gradients, the process achieves uniform step coverage across complex three-dimensional structures while maintaining high overall deposition 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 method increases the deposition rate and improves the step coverage and quality of the film layer, preventing wafer scrapping and enhancing product yield by gently removing defective layers and optimizing surface contact resistance.
Implementation Method 1
the reaction source gas is formed into plasma, and the plasma is deposited on the substrate based on the attachment points to form a first film layer
Data Source
AI summary
A method for forming a film layer includes: a substrate is provided; a pretreatment step is performed, in which the pretreatment step includes providing a reaction source gas, which forms attachment points on the substrate; and a deposition step is performed, in which the reaction source gas is formed into a plasma, which is deposited on the substrate based on the attachment points to form a first film layer.