Semiconductor Device Central Area Sacrificial Layer Replacement
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Solution Overview
Problem
In the manufacturing of three-dimensional semiconductor memory devices, it is challenging to replace sacrificial layers in the central area of memory blocks due to difficulties in accessing and introducing replacement materials effectively.
Innovation Solution
The method involves forming a stacked structure with alternately stacked first and second material layers, creating holes and channel structures that allow for the replacement of the second material layers with new material patterns, including the use of interlayer insulating layers and conductive patterns, and employing sidewall insulating layers and conductive contact pillars to facilitate the introduction of replacement materials into the central area of memory blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If sacrificial layers are arranged in a central area of a memory block, then integration density is improved, but replacement of sacrificial layers becomes difficult
Solution Approach 1:
The memory block is divided into multiple memory holes, and sacrificial layers are segmented into portions corresponding to each memory hole. This segmentation allows selective access and replacement of individual sacrificial layer portions through specific holes, solving the problem of inaccessible central area sacrificial layers.
Solution Approach 2:
Etch holes are introduced as intermediary pathways to access sacrificial layers in the central area. These holes serve as mediators that enable replacement materials to reach previously inaccessible sacrificial layer portions through the stacked structure.
2Device complexity
If replacement materials are introduced through existing holes, then manufacturing process is simplified, but access to central area sacrificial layers is insufficient
Solution Approach 1:
The access pathway is segmented into two types of holes: etch holes for accessing sacrificial layers and replacement holes for introducing replacement materials. This segmentation allows each hole type to serve its specific function efficiently, with etch holes providing access and replacement holes enabling material introduction.
Solution Approach 2:
Etch holes act as intermediary structures that are formed first to access sacrificial layers, which then serve as templates or guides for forming replacement holes. The etch holes mediate between the surface and the central area sacrificial layers, enabling subsequent replacement hole formation.
Data Source
AI summary
A method of manufacturing a semiconductor device includes forming holes passing through a stacked structure, surrounding channel structures, and replacing some of the materials of the stacked structure through the holes.