TFT Spacer Layer Isolates N-I Junction to Reduce Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thin film transistors (TFTs) experience excessive current leakage due to electron flow through the N-I junction between the amorphous silicon layers, leading to instability in semiconductor devices with high integration.
Innovation Solution
A spacer layer, typically an oxide layer formed by oxygen plasma treatment, is introduced at the sidewalls of the N-I junction to isolate the insulating layer from direct contact with the junction region, preventing current leakage and enhancing stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insulating layer is formed directly on the channel region without a spacer layer, then the manufacturing process is simpler, but current leakage occurs through the N-I junction between the amorphous silicon layers
Solution Approach 1:
An oxide spacer layer is introduced as an intermediary between the n+ amorphous silicon layer and the insulating layer. This spacer layer prevents direct contact between the N-I junction and the insulating layer, thereby blocking the leakage current path while maintaining the overall device structure
Solution Approach 2:
The interface region between the amorphous silicon layer and the insulating layer is segmented by introducing the oxide spacer layer. This segmentation separates the N-I junction from the insulating layer, creating distinct functional zones that prevent harmful electron flow while maintaining manufacturing feasibility
2Stability of the object's composition
If the insulating layer directly contacts the N-I junction, then the device structure is simpler, but electrical stability deteriorates due to excessive current leakage
Solution Approach 1:
The oxide spacer layer serves as a mediator that isolates the N-I junction from the insulating layer, preventing the harmful interaction that causes current leakage and electrical instability, while adding only a thin intermediate layer to the structure
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 spacer layer significantly reduces current leakage, improving the electrical characteristics and stability of the TFT structure by preventing direct contact between the N-I junction and the insulating layer, thereby minimizing undesirable electron flow.
Implementation Method 1
A spacer layer, typically an oxide layer formed by oxygen plasma treatment, is introduced at the sidewalls of the N-I junction
Implementation Method 2
A spacer layer, typically an oxide layer formed by oxygen plasma treatment
Data Source
AI summary
In a thin film transistor (TFT) structure, formation of a spacer layer is used for isolating the NI junction from an insulating layer comprising a nitride, so as to decrease the amount of current leakage and improve the electric characteristics of TFT. In a back-channel etching (BCE) type TFT device, the spacer layer (comprising an oxide layer) is substantially formed at the sidewalls of the channel regions to isolate the insulating layer (comprising silicon nitride) from the NI junctions. In an etch-stop TFT device, the spacer layer (comprising an oxide layer) is substantially formed at the sidewalls of the etch-stop layer to isolate the insulating layer (i.e. etch-stop layer) from the NI junctions.