Semiconductor devices and methods of fabrication

US10608004B2 · kind B2 · utility

Assignee

• Micron Technology, Inc. · US

Inventors

• Hongbin Zhu · Boise, US
• Zhenyu Lu · Hubei, CN
• Gordon A. Haller · Boise, US
• Jie Sun · San Diego, US
• Randy J. Koval · Boise, US
• John D. Hopkins · Meridian, US

Key dates

• Filing date: Jul 5, 2018
• Grant date: Mar 31, 2020
• Expiry date: Jul 5, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/685

Abstract

Some embodiments include a semiconductor device having a stack structure including a source comprising polysilicon, an etch stop of oxide on the source, a select gate source on the etch stop, a charge storage structure over the select gate source, and a select gate drain over the charge storage structure. The semiconductor device may further include an opening extending vertically into the stack structure to a level adjacent to the source. A channel comprising polysilicon may be formed on a side surface and a bottom surface of the opening. The channel may contact the source at a lower portion of the opening, and may be laterally separated from the charge storage structure by a tunnel oxide. A width of the channel adjacent to the select gate source is greater than a width of the channel adjacent to the select gate drain.