THREE-DIMENSIONAL VERTICAL NONVOLATILE MEMORY DEVICE INCLUDING MEMORY CELL STRING

Smart overview of the Invention

The patent application describes a three-dimensional vertical non-volatile memory device featuring a memory cell string. This device comprises multiple memory cell strings, each containing a channel layer, gate electrodes, spacers, an ion reservoir layer, and an electrolyte layer. These components are arranged to facilitate ion movement between the ion reservoir layer and the channel layer, controlled by voltage applied to the gate electrodes. This design aims to enhance memory storage capabilities by efficiently managing ion movement and resistance within the device.

Components and Materials

The memory device utilizes a specific arrangement of layers and materials to achieve its functionality. The ion reservoir and electrolyte layers are made of metal oxide materials, such as tantalum oxide or hafnium oxide, which assist in ion movement. The channel layer may include materials like indium-gallium-zinc oxide. The thickness of these layers is carefully controlled, typically ranging from 2 nm to 10 nm, to optimize performance. Additionally, a barrier layer is included to separate certain components, made from materials like silicon oxide or silicon nitride.

Functionality

The device's operation is based on the movement of ions between the ion reservoir and channel layers, influenced by applied voltages. Positive write voltages move ions to the channel layer, decreasing its resistance, while negative erase voltages return ions to the reservoir, increasing resistance. In a floating state, ions remain stationary, preventing unintended data changes. The device can perform read operations using specific voltages, allowing for data retrieval by measuring current flow through the channel layer.

Performance Characteristics

Different voltages applied to the gate electrodes result in varying current flows, which determine the memory state. A low resistance current indicates a written state, while a high resistance current signifies an erased state. The design ensures that the current flow during a pass voltage remains consistent, regardless of the resistance state. This careful control of current and resistance enhances the device's reliability and efficiency.

Integration and Application

This memory device can be integrated into electronic devices, working alongside processing circuitry to provide non-volatile memory storage. Its design supports high integration and capacity, making it suitable for various applications, including mobile phones and computers. By leveraging advanced materials and precise engineering, the device offers improved data reliability, speed, and power efficiency, addressing the challenges of modern memory storage technology.