Semiconductor Storage Device Hydrogen Diffusion Barrier
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Solution Overview
Problem
Hydrogen atoms incorporated into silicon oxide layers during the CVD process can diffuse through the layers and affect transistor characteristics, leading to variations and degradations in transistor performance due to their interaction with dopants in the gate electrode made of polycrystalline silicon.
Innovation Solution
The semiconductor storage device incorporates a silicon nitride sidewall layer and a second insulating layer to prevent hydrogen diffusion, with the edge seal portion extending through the silicon oxide film and connected to the substrate, effectively blocking hydrogen from reaching the transistor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a silicon oxide layer is deposited using CVD method, then the insulating layer is formed, but hydrogen atoms are incorporated into the silicon oxide layer and diffuse to the transistor, causing variations and degradations in transistor characteristics
Solution Approach 1:
A silicon nitride layer is introduced as an intermediary barrier between the silicon oxide layer and the transistor. This silicon nitride layer has low hydrogen permeability and acts as a mediator to block hydrogen atoms from diffusing from the silicon oxide layer to the transistor, thereby preventing transistor characteristic degradation while maintaining the insulating function of the silicon oxide layer
Solution Approach 2:
The structure combines silicon oxide and silicon nitride layers to create a composite insulating system. The silicon oxide layer provides the primary insulating function, while the silicon nitride layer provides hydrogen barrier functionality, creating a multi-functional composite structure that simultaneously achieves electrical insulation and hydrogen protection
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 configuration significantly reduces hydrogen diffusion to the transistor, minimizing variations and degradations in transistor characteristics and maintaining stable threshold voltage.
Implementation Method 1
a silicon nitride sidewall layer and a second insulating layer are provided to prevent hydrogen diffusion
Data Source
AI summary
A semiconductor storage device according to one embodiment includes a substrate; a memory cell area having a stacked body where plural electrically conductive layers and plural first insulating layers are stacked alternately one on another, and a pillar portion that penetrates through the stacked body and provides plural memory cells; a peripheral circuit portion that intervenes between the substrate and the memory cell area, and includes a peripheral circuit for plural memory cells; a first plate-like portion that has a frame-like plan view shape and surrounds the peripheral circuit portion, the first plate-like portion being electrically conductive and connected at a lower end thereof to the substrate; a sidewall layer including silicon nitride on a side surface of the first plate-like portion; and a second insulating layer including silicon nitride, the second insulating layer being connected to the sidewall layer and covering above the peripheral circuit portion.