Oxide Semiconductor Nanostructure Formation via Oxygen Scavenging
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Solution Overview
Problem
The semiconductor industry faces challenges in forming reliable semiconductor devices at increasingly smaller sizes due to the complexity and difficulty of fabrication processes as feature sizes decrease, affecting production efficiency and cost.
Innovation Solution
The process involves forming a stack with alternating sacrificial and oxide semiconductor layers, trimming oxide semiconductor nanostructures to enhance resistance, introducing oxygen to form channels with specific dopant concentrations, and using oxygen scavenging to create source/drain structures with higher dopant concentrations, followed by the formation of a gate stack around these structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency and cost are improved, but fabrication process complexity and difficulty increase
Solution Approach 1:
The fabrication process is divided into multiple sequential steps including forming sacrificial layers, forming oxide semiconductor layers, selective removal of sacrificial layers, and forming gate electrodes. This segmentation allows each step to be optimized independently while maintaining overall process control despite decreasing feature sizes
Solution Approach 2:
Sacrificial layers are formed in advance before the oxide semiconductor layers are created. These preliminary sacrificial structures guide the subsequent formation processes and enable precise positioning of the semiconductor channels before the actual device fabrication begins
2Reliability
If oxide semiconductor nanostructures are trimmed to enhance resistance, then threshold voltage is improved, but manufacturing precision requirements increase
Solution Approach 1:
The oxide semiconductor layers are selectively removed in specific regions through the sacrificial layer pattern, creating local variations in semiconductor material presence. This local quality control allows threshold voltage adjustment in specific device regions without affecting the entire wafer uniformly
Solution Approach 2:
Sacrificial layers serve as intermediary structures that mediate the trimming process. These temporary structures enable precise definition of the oxide semiconductor regions without requiring direct manipulation of the semiconductor material itself, thereby reducing manufacturing precision requirements
3Reliability
If oxygen is introduced to form channels with specific dopant concentrations, then device performance is enhanced, but process time and complexity increase
Solution Approach 1:
Oxygen is introduced into the oxide semiconductor layers during the layer formation process itself, rather than requiring a separate post-processing step. This preliminary oxygen incorporation achieves the desired dopant concentrations while integrating the doping function into the existing fabrication sequence
Solution Approach 2:
The oxygen introduction process is merged with the oxide semiconductor layer formation process. By combining these two functions into a single process step, the patent achieves dopant incorporation without adding separate process time for oxygen treatment
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 approach improves the performance and reliability of transistors by optimizing dopant concentrations and reducing oxygen vacancies, leading to enhanced threshold voltage and overall device performance.
Implementation Method 1
introducing oxygen into the oxide semiconductor nanostructures
Implementation Method 2
oxygen scavenging to create source/drain structures
Data Source
AI summary
A method for forming a semiconductor device structure is provided. The method includes forming a stack over a substrate. The stack has multiple sacrificial layers and multiple oxide semiconductor layers laid out alternately. The method also includes partially removing the sacrificial layers to expose inner portions of the oxide semiconductor layers. The inner portions of the oxide semiconductor layers form multiple oxide semiconductor nanostructures. The method further includes changing an atomic concentration of oxygen of the oxide semiconductor nanostructures. In addition, the method includes forming a gate stack wrapped around one or more of the oxide semiconductor nanostructures after the changing of the atomic concentration of oxygen of the oxide semiconductor nanostructures.