OLED Transistor Gate Slope and Doping Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current display devices, particularly organic light emitting diode (OLED) displays, face challenges in transistor design due to the need for different transistor groups with varying characteristics, such as leakage current reliability and charge mobility, which complicates manufacturing and increases costs.
Innovation Solution
The design incorporates a pixel driving circuit with first and second transistors having gate electrodes with distinct lateral wall slope angles, where the first transistor includes a doping control member on its lateral wall to form a lightly doped drain, while the second transistor does not, simplifying the manufacturing process and reducing costs by eliminating the need for additional masks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If different transistor groups with varying characteristics are designed to meet different requirements, then reliability and performance are improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies local quality by forming a doping control member selectively on the lateral wall of the gate electrode only for the first transistor group, not for the second transistor group. This creates locally differentiated doping regions that provide different characteristics (higher doping concentration for first group, lower for second group) without requiring completely different transistor structures, thus improving reliability while limiting complexity increase.
Solution Approach 2:
The patent changes the doping concentration parameter differently for the two transistor groups by using a doping control member for the first group only. This parameter differentiation allows each transistor group to be optimized for its specific function (switching vs. driving) without requiring fundamental design changes, resolving the contradiction between reliability and complexity.
2Reliability
If additional doping control members and masks are used to create different transistor characteristics, then transistor performance is improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The doping control member is formed locally only on the lateral wall of the gate electrode for the first transistor group, allowing selective doping without requiring separate processing lines for different transistor types. This local differentiation improves manufacturing efficiency by avoiding the need for multiple masks while still achieving the required performance differentiation.
Solution Approach 2:
The patent merges the formation of the doping control member with the existing gate electrode fabrication process. By integrating the doping control member formation into the standard manufacturing flow rather than adding completely separate steps, the patent improves transistor reliability while minimizing the increase in manufacturing complexity and cost.
3Ease of manufacture
If uniform doping is applied to all transistors, then manufacturing process is simplified, but leakage current increases and reliability decreases
Solution Approach 1:
The doping control member creates a localized high-doping region on the lateral wall of the gate electrode for the first transistor group, forming a lightly doped drain that specifically targets leakage current reduction where it occurs most. This local doping approach maintains manufacturing simplicity while effectively reducing leakage current without requiring uniform doping changes across all transistors.
Solution Approach 2:
The doping control member structure serves as a template that replicates the desired doping pattern automatically during the doping process. By creating this control structure once during gate fabrication, the same doping pattern is consistently reproduced for all first transistor groups, simplifying the overall doping process while achieving the leakage reduction benefit.
Data Source
AI summary
A display device according to an exemplary embodiment of the present invention includes: a substrate; a plurality of transistors formed on the substrate; and a light-emitting device connected to the plurality of transistors, wherein the transistor includes a gate electrode, the plurality of transistors include a first transistor and a second transistor of which lateral wall slope angles of the gate electrode are different from each other, and the first transistor further includes a doping control member formed on a lateral wall of the gate electrode.