Polysilicon Grain Size Control via Seed Layer Vacuuming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for forming semiconductor films struggle to effectively control the grain size of crystallized semiconductor films, which is crucial for various applications such as thin film transistors and memory devices, as they often require either large or small grain sizes depending on their purpose.
Innovation Solution
A method involving the formation of a seed layer on a substrate, followed by vacuuming the processing container to a medium vacuum, and then crystallizing an amorphous silicon film by heat processing, where the grain size is controlled by adjusting the duration of the vacuuming process or the seed layer formation time, allowing for precise control over the grain size of the poly silicon film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If impurity doping is used to control grain size, then grain size control is achieved, but manufacturing complexity and process difficulty increase
Solution Approach 1:
The invention extracts and removes the impurity doping step from the conventional process. Instead of adding carbon impurities to control grain size, the method uses a simplified process where the amorphous silicon film is directly crystallized through heat treatment, achieving grain size control through thermal processing parameters rather than chemical composition control
Solution Approach 2:
The invention changes the control parameter from chemical composition (impurity concentration) to thermal processing parameters (heating temperature and time). By adjusting the crystallization temperature and duration, precise grain size control is achieved without the complexity of impurity doping processes
2Manufacturing precision
If conventional crystallization methods are used, then poly silicon film is formed, but grain size control is insufficient
Solution Approach 1:
The invention performs preliminary action by forming a carefully controlled seed layer before the main crystallization process. This seed layer, created under specific vacuum conditions, provides a foundation that directs subsequent grain growth, enabling better grain size control in the final poly silicon film
Solution Approach 2:
The invention uses a vacuum environment (inert atmosphere) during seed layer formation and film deposition. This controlled inert environment prevents contamination and ensures consistent crystallization behavior, leading to improved film quality and reliable grain size 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
This method enables the formation of semiconductor films with controlled grain sizes without the need for impurity doping, allowing for tailored properties suitable for different applications by varying the vacuuming or seed layer formation time, thereby enhancing the versatility and performance of semiconductor films.
Implementation Method 1
vacuuming an interior of the processing container to a medium vacuum or less
Implementation Method 2
crystallizing the amorphous semiconductor film by heat processing
Implementation Method 3
crystallizing the amorphous semiconductor film by heat processing
Data Source
AI summary
According to one embodiment of the present disclosure, a method for forming a crystallized semiconductor film having a specific grain size on a substrate includes: forming a seed layer on the substrate accommodated in a processing container; vacuuming an interior of the processing container to a medium vacuum or less in a state in which the substrate, on which the seed layer is formed, is accommodated in the processing container; forming an amorphous semiconductor film on the seed layer after vacuuming the interior of the processing container; and crystallizing the amorphous semiconductor film by heat processing.