Oxide Semiconductor Device With Flat Plate Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in fabricating semiconductor devices with high integration and high-speed requirements, where oxide semiconductor layers face difficulties in forming array structures with fine pitches due to contamination issues during dry etching, leading to leakage current problems and the need for device isolation structures.
Innovation Solution
A semiconductor device is developed where oxide semiconductor layers are continuously formed across active and isolation regions without etching, using a flat plate structure and gate metal layers to create electrical insulation, allowing transistors to operate independently without physical device isolation, and applying a negative bias to maintain an insulated state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dry etching is used to form array structures with fine pitches, then manufacturing precision is improved, but contamination occurs leading to leakage current
Solution Approach 1:
The patent extracts the harmful etching process entirely from the fabrication sequence. Instead of using dry etching to pattern the oxide semiconductor layer, the invention forms continuous oxide semiconductor layers across all regions and uses selective gate electrode formation to define device regions, thereby eliminating contamination from etching while maintaining fine pitch array structure formation capability
Solution Approach 2:
The gate electrode structure serves as an intermediary that performs the dual function of electrical control and physical separation. By forming gate electrodes selectively over active regions using the oxide semiconductor layer as a mask, the invention uses this intermediate structure to define device boundaries without requiring etching of the oxide semiconductor layer itself
2Reliability
If device isolation structures are formed to prevent leakage current, then reliability is improved, but device complexity and fabrication steps increase
Solution Approach 1:
The oxide semiconductor layer is given multiple functions: it serves as the active channel material in transistors, as an etching mask for forming gate electrodes, and as an insulating layer that provides electrical isolation between adjacent devices. This multi-functionality eliminates the need for separate device isolation structures while maintaining reliability
Solution Approach 2:
The invention merges the channel formation and device isolation functions into a single continuous oxide semiconductor layer structure. By combining these functions and using selective gate electrode formation, the patent reduces fabrication complexity while ensuring proper electrical isolation between devices
3Ease of operation
If oxide semiconductor layers are etched to form device isolation, then device separation is achieved, but manufacturing precision deteriorates due to contamination
Solution Approach 1:
Instead of etching the oxide semiconductor layer to achieve device separation, the invention inverts the approach by forming continuous oxide semiconductor layers and using selective deposition of gate electrodes to achieve the same separation effect. This inversion eliminates etching-related contamination while maintaining device electrical separation
Data Source
AI summary
A semiconductor device includes: a substrate including an active region and a device isolation region; a flat plate structure formed on the substrate; an oxide semiconductor layer covering a top surface of the flat plate structure and continuously arranged on a top surface of the substrate in the active region and the device isolation region; a gate structure arranged on the oxide semiconductor layer and including a gate dielectric layer and a gate electrode; and a source/drain region arranged on both sides of the gate structure and formed in the oxide semiconductor layer, in which, when viewed from a side cross-section, an extending direction of the flat plate structure and an extending direction of the gate structure cross each other.