Vertical thin film transistors in non-volatile storage systems
US9362338B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2014 |
| Grant date | Jun 7, 2016 |
| Priority date | — |
| Expiry date | Mar 3, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N70/8833
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Each gate is formed over the gate dielectric and a base that extends horizontally at least partially between adjacent pillars. The base is formed with notches filled with the gate dielectric. The select device is fabricated using a conformally deposited base dielectric material and conformal hard mask layer that is formed with a larger bottom thickness than horizontal thickness. The base thickness is defined by the deposition thickness, rather than an uncontrolled etch back.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.