Vertical Channel Memory Device with Arc Segments

The patent transitions from planar 2D memory architecture to three-dimensional vertical channel architecture. The vertical channels extend in the depth direction from the substrate surface, utilizing the third dimension (Z-axis) to increase storage capacity without expanding the planar footprint. This dimensional transition enables higher memory density while maintaining fast access speeds characteristic of DRAM.

The memory device is segmented into multiple vertical channels, each containing distinct functional regions (charge trapping structure, first memory cell region, second memory cell region). Each vertical channel is further divided into multiple memory cells through word line separation, allowing independent addressing and access. This segmentation enables parallel operations and increases overall memory capacity within a compact form factor.

Different regions within each vertical channel are assigned different functional qualities: the charge trapping structure provides non-volatile storage capability, the first memory cell region optimized for fast access, and the second memory cell region for additional capacity. This local differentiation allows the device to exhibit both high-speed DRAM-like access and high-density NAND flash-like storage in the same structure.

The memory device employs composite material structures including oxide-nitride-oxide stacks for charge trapping, alternating oxide and nitride layers for tunnel barriers and charge storage, and conductive materials for word lines and bit lines. These composite structures enable simultaneous achievement of fast write/read operations and high storage density by combining materials with complementary properties.

The oxide-nitride-oxide charge trapping structure and alternating oxide-nitride memory cell region structures are formed as preliminary layers before vertical channel patterning. The tunnel oxide layers, charge trapping layers, and barrier layers are deposited in advance using atomic layer deposition (ALD), creating a pre-fabricated stack that simplifies subsequent vertical channel formation and reduces overall manufacturing steps.

Traditional mechanical patterning methods are replaced with atomic layer deposition (ALD) for forming ultra-thin oxide and nitride layers with precise thickness control. ALD enables conformal coating of complex three-dimensional structures and provides atomic-level thickness precision, replacing multiple mechanical deposition and etching steps with a more efficient vapor-phase deposition process.