Important Process Parameter And Its Sensitivity Check By Virtual Fabrication: Channel Hole Profile Impact On Advanced 3D NAND Structure

A virtual DOE-based process sensitivity check was performed for two tiers of channel holes in a 3D NAND device. The channel hole tilt distance, twist angle, and their sensitivities to the visible area in silicon-oxide-nitride-oxide (SONO) punch process were analyzed. The results show that controlling the upper tilt distance is more important for offering a larger visible area. Also, a negative ... » read more

Untangling 3D NAND: Tilt, Registration, And Misalignment

The multiple demands of 3D NAND to enable yield and performance increase in difficulty at each generation. First generation devices, at 24-32 layer pairs, pushed process tools to extremes, going quickly from 10:1 to 40:1 aspect ratios for today’s 64-96 pair single tier devices. The aspect ratios increased as fast as the manufacturing challenges. To continue bit density scaling, processing imp... » read more