3D memory having crystalline silicon NAND string channel

US9287290B1 · kind B1 · utility

Assignee

• Sandisk Technologies, Inc. · US

Inventors

• Peter Rabkin · Cupertino, US
• Jayavel Pachamuthu · Milpitas, US
• Johann Alsmeier · San Jose, US
• Masaaki Higashitani · Cupertino, US

Key dates

• Filing date: Feb 11, 2015
• Grant date: Mar 15, 2016
• Expiry date: Feb 11, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B41/27

Abstract

Disclosed herein are 3D NAND memory devices having vertical NAND strings with a crystalline silicon channel and techniques for fabricating the same. The NAND string channel may be a single crystal of silicon or have a few large grains of polysilicon. The single crystal may have a (100) orientation with respect to a tunnel oxide of the 3D NAND string. When the channel region comprises grains of polysilicon, predominantly all of the silicon channel is part of a grain of polysilicon having the (100) orientation. The (100) orientation may be favorable for high carrier mobility. Techniques using metal induced crystallization (MIC) for forming the NAND strings having a crystalline silicon channel are also disclosed.