Semiconductor Gate Dielectric Interface Engineering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Three-dimensional memory devices face challenges with signal conflict and interference due to the use of polycrystalline silicon channel material, leading to poor interface quality between the storage and tunneling layers in the gate dielectric, which affects erase speed and reliability.
Innovation Solution
A method is introduced to improve the interface quality by adding a first and second interface layer between the storage and tunneling layers, using oxidation and deposition processes to control the composition and nitrogen concentration, allowing for flexible adjustment of nitrogen peak concentration and location, and converting an amorphous material layer to polycrystalline material through annealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polycrystalline silicon channel material is used in three-dimensional memory devices, then the device structure can be implemented, but the interface quality between storage and tunneling layers deteriorates
Solution Approach 1:
The patent introduces interface layers as separate segments between the storage layer and tunneling layer. This segmentation creates distinct functional zones that improve interface quality by providing graded transitions and reducing direct contact between materials with large lattice mismatches, thereby resolving the contradiction between manufacturability and interface precision.
Solution Approach 2:
The interface layers act as intermediary structures between the storage layer and tunneling layer. These intermediate layers with graded composition serve as mediators that reduce interface defects and improve overall interface quality, allowing the device structure to be manufactured while maintaining high precision interfaces.
2Speed
If nitrogen concentration in the tunneling layer is increased to improve erase speed, then hole tunneling probability increases, but interface quality and device reliability may deteriorate
Solution Approach 1:
The patent applies local quality by creating interface layers with graded nitrogen concentration profiles. The nitrogen concentration is locally optimized at different positions: higher near the storage layer for fast erase speed, and lower near the tunneling layer for maintaining interface quality and reliability, thus resolving the contradiction between speed and reliability.
Solution Approach 2:
The patent changes the nitrogen concentration parameter gradually across the interface layers rather than using a uniform concentration. This parameter gradient allows the device to achieve fast erase speed in the storage interface region while maintaining reliability in the tunneling interface region, resolving the contradiction between these two requirements.
3Device complexity
If the gate dielectric structure is simplified to reduce process complexity, then manufacturing becomes easier, but the ability to control interface quality and nitrogen peak location is reduced
Solution Approach 1:
The patent introduces dynamically adjustable interface layers with variable thickness and composition profiles. These layers provide dynamic control over interface quality and nitrogen peak location through process parameter adjustments, resolving the contradiction between structural simplicity and control flexibility by adding programmable complexity.
Solution Approach 2:
The patent adds the dimension of compositional gradient control to the gate dielectric structure. By introducing interface layers with graded nitrogen concentration, the patent transforms a two-dimensional structure problem into a three-dimensional compositional control problem, enabling flexible adjustment of interface properties without significantly increasing overall device complexity.
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 enhances the quality of the interface between the storage and tunneling layers, improving the reliability and current characteristics of the device, while increasing process flexibility.
Implementation Method 1
performing oxidation and deposition processes, to form a first interface layer on the storage layer
Implementation Method 2
performing oxidation and deposition processes, to form a first interface layer on the storage layer
Implementation Method 3
performing annealing, forming a second interface layer on surface of the tunneling layer; converting an amorphous material layer to polycrystalline material through annealing
Data Source
AI summary
A semiconductor device comprise a substrate, source/drain regions, a channel region, a gate dielectric layer and a gate conductive layer, wherein the gate dielectric layer comprises a barrier layer, a storage layer, a first interface layer, a tunneling layer, a second interface layer. In accordance with the semiconductor device and the manufacturing method of the present invention, an interface layer is added between the storage layer and tunneling layer in the gate dielectric by adjusting process step, and the peak concentration and peak location of nitrogen can be flexibly adjusted, effectively improving the quality of the interface between the storage layer and the tunneling layer in the gate dielectric layer, increasing process flexibility, improving device reliability and current characteristics.