Antenna Diodes for Charge Discharge in 3D Memory Etching
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Solution Overview
Problem
Plasma etch processes in three-dimensional memory devices can lead to local electrical discharge and charge buildup, causing distortions in the shape of etched openings, such as backside trenches, due to the dielectric material layers used in the alternating stack of insulating and spacer layers.
Innovation Solution
Incorporating antenna diodes on the semiconductor substrate, which are electrically shorted to lower-level metal interconnect structures, to prevent charge buildup by providing a discharge path for electrical charges during plasma etching, thus maintaining the vertical integrity of the trenches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dielectric material layers are used in the alternating stack for plasma etching, then the etching process can be performed, but local electrical discharge and charge buildup occur causing distortions in the shape of etched openings
Solution Approach 1:
Antenna diodes are introduced as intermediary structures to provide a controlled discharge path for electrical charges during plasma etching. The diodes act as mediators between the plasma process and the dielectric layers, preventing charge buildup that would otherwise cause distortions in etched opening shapes while maintaining the plasma etching process capability
2Manufacturing precision
If antenna diodes are added to prevent charge buildup, then shape precision of etched openings is improved, but device complexity increases
Solution Approach 1:
Rather than modifying the entire device structure, antenna diodes are strategically placed only at specific locations where charge buildup problems occur during plasma etching. This localized approach provides the necessary charge dissipation function without adding complexity to the entire device, maintaining simplicity while improving etching precision
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
The use of antenna diodes effectively reduces or prevents charge accumulation, ensuring straight vertical profiles of backside trenches and improving the precision of plasma etching processes in three-dimensional memory devices.
Implementation Method 1
Incorporating antenna diodes on the semiconductor substrate, which are electrically shorted to lower-level metal interconnect structures, to prevent charge buildup by providing a discharge path for electrical charges during plasma etching
Implementation Method 2
Plasma etch processes in three-dimensional memory devices can lead to local electrical discharge and charge buildup, causing distortions in the shape of etched openings
Data Source
AI summary
At least one diode, lower-level metal interconnect structures embedded within lower-level dielectric material layers, and a doped semiconductor material layer are formed over a semiconductor substrate. An electrically conductive path is provided between the at least one diode and the doped semiconductor material layer. An alternating stack of insulating layers and spacer material layers and memory stack structures extending therethrough are formed above the doped semiconductor material layer. A backside trench is formed through the alternating stack. The electrically conductive path is employed during plasma etch processes employed to form the memory stack structures and the backside trench to provide a discharge path for accumulated electrical charges. The electrically conductive path is subsequently disconnected by removing a conductive component underlying the backside trench. The spacer material layers can be replaced with electrically conductive layers employing the backside trench.