Superlattice Gettering Layer for MIC Memory Defect Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor devices face limitations in enhancing charge carrier mobility and reducing defects, particularly in 3D NAND memory devices, where metal diffusion can lead to crystalline defects and yield reduction.
Innovation Solution
The implementation of a superlattice gettering layer, comprising a plurality of stacked groups of layers with non-semiconductor monolayers constrained within the crystal lattice of adjacent semiconductor portions, which acts as a barrier to dopant and material diffusion, and includes metal-induced crystallization (MIC) channels with gettered metal particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal-induced crystallization (MIC) is used to form channels in 3D NAND memory devices, then crystalline structure is achieved, but metal particles diffuse and cause crystalline defects
Solution Approach 1:
A superlattice gettering layer is introduced as an intermediary structure between the MIC channel and the substrate. This superlattice comprises alternating layers of silicon and silicon-germanium with different lattice constants, creating a strained superlattice that acts as a gettering layer to trap and contain metal particles, preventing their diffusion into the crystalline channel structure.
Solution Approach 2:
The superlattice gettering layer is formed using composite materials - alternating layers of silicon and silicon-germanium with different germanium concentrations. This composite structure creates lattice mismatch and strain that enables effective metal particle gettering while maintaining structural integrity and preventing defect formation in the MIC channel.
2Speed
If charge carrier mobility is enhanced through strained material layers, then device performance improves, but charged impurities and defects increase
Solution Approach 1:
The superlattice gettering layer serves as an intermediary that separates the strained channel region from the substrate. It getters charged impurities and metal particles away from the high-mobility channel, allowing the strained material to maintain its performance benefits without being contaminated by defects and charged impurities.
Solution Approach 2:
The device structure is segmented into distinct functional regions: the strained channel for high mobility, the superlattice gettering layer for impurity separation, and the substrate for structural support. This segmentation allows each region to optimize its function while preventing harmful interactions between regions.
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 charge carrier mobility by reducing charged impurity concentration and improving interface quality, while effectively containing metal particles and reducing crystalline defects, thereby improving device performance and yield.
Implementation Method 1
The superlattice gettering layer may include gettered metal particles from the MIC channel
Implementation Method 2
acts as a barrier to dopant and material diffusion
Data Source
AI summary
A method for making a semiconductor device may include forming a superlattice gettering layer on a substrate. The superlattice may include a plurality of stacked groups of layers, with each group of layers comprising a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may also include forming a memory device above the superlattice gettering layer including a metal induced crystallization (MIC) channel adjacent the semiconductor substrate, and a gate associated with the MIC channel. The superlattice gettering layer may further include gettered metal particles from the MIC channel.