Oxide Semiconductor Pattern Repair After Etching Damage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oxide semiconductors used in semiconductor devices suffer from etching damage during patterning, leading to thickness reduction, surface irregularities, and increased susceptibility to impurity penetration, which affect device performance and integration.
Innovation Solution
A method involving the formation of a crystalline first oxide semiconductor pattern followed by a crystalline second oxide semiconductor layer on the etched surface to compensate for etching damage, using methods like vapor deposition or epitaxial growth to restore thickness and smoothness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If an etching process is used to pattern the oxide semiconductor layer, then the desired pattern shape is achieved, but etching damage occurs causing thickness reduction and surface irregularities
Solution Approach 1:
A buffer layer is formed on the substrate before forming the oxide semiconductor layer. This preliminary action provides a protective foundation that prevents etching damage from penetrating to the substrate, thereby maintaining thickness uniformity while still allowing pattern formation through etching.
Solution Approach 2:
The buffer layer is strategically positioned only where needed - on the substrate beneath the oxide semiconductor layer. This localized protection allows etching to proceed normally for pattern formation while preventing damage at the critical substrate interface, resolving the contradiction between achieving pattern shape and maintaining thickness precision.
2Shape
If an etching process is used to pattern the oxide semiconductor layer, then the desired pattern shape is achieved, but surface irregularities and impurity penetration increase
Solution Approach 1:
The buffer layer acts as a cushioning layer formed beforehand on the substrate. During the etching process, this buffer layer absorbs and protects against etching damage, preventing surface irregularities and impurity penetration while still allowing the oxide semiconductor layer to be properly patterned.
Solution Approach 2:
The buffer layer serves as an intermediary between the substrate and the oxide semiconductor layer. It mediates the etching process by providing a protective interface that prevents direct contact between the etching plasma and the substrate, thereby reducing harmful effects while maintaining pattern formation capability.
3Manufacturing precision
If amorphous silicon is used for the semiconductor layer, then device characteristics are uniform and manufacturing is simple, but carrier mobility is low
Solution Approach 1:
The invention changes the material parameter from amorphous silicon to oxide semiconductor, which fundamentally alters the electrical properties. Oxide semiconductors inherently provide higher carrier mobility while maintaining the ability to achieve uniform device characteristics through controlled deposition processes, thus resolving the contradiction between uniformity and mobility.
4Reliability
If polysilicon is used for the semiconductor layer, then carrier mobility is high, but a recrystallization process is required and device characteristics uniformity is difficult to secure
Solution Approach 1:
The invention changes the material parameter from polysilicon to oxide semiconductor. This eliminates the need for recrystallization processes while maintaining high carrier mobility. The oxide semiconductor can be deposited in a crystalline state directly, providing both high mobility and uniform device characteristics without the complex thermal processing required for polysilicon.
Solution Approach 2:
The invention extracts and eliminates the problematic recrystallization step from the manufacturing process. By using oxide semiconductor material that can be deposited in a desired crystalline state directly, the patent removes the need for subsequent high-temperature annealing and recrystallization processes that compromise device uniformity, while still achieving high carrier mobility.
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 method effectively mitigates etching damage by restoring thickness and reducing impurity penetration, enhancing the performance and reliability of semiconductor devices.
Implementation Method 1
forming a crystalline second oxide semiconductor layer on the etched surface
Implementation Method 2
using methods like vapor deposition or epitaxial growth to restore thickness and smoothness
Data Source
AI summary
A semiconductor device includes a crystalline first oxide semiconductor pattern having at least one etched surface; and a crystalline second oxide semiconductor layer disposed on the etched surface of the first oxide semiconductor pattern. A method for fabricating a semiconductor device includes forming a crystalline first oxide semiconductor layer over a substrate; forming a first oxide semiconductor pattern having an etched side surface by selectively etching the first oxide semiconductor layer; and forming a crystalline second oxide semiconductor layer on the side surface of the first oxide semiconductor pattern.