Semiconductor memory device with stacked control transistors
US7453716B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2005 |
| Grant date | Nov 18, 2008 |
| Priority date | — |
| Expiry date | Sep 29, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2213/79
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a semiconductor memory device and method, phase-change memory cells are provided, each including a plurality of control transistors formed on different layers and variable resistance devices formed of a phase-change material. Each phase-change memory cell includes a plurality of control transistors formed on different layers, and a variable resistance device formed of a phase-change material. In one example, the number of the control transistors is two. The semiconductor memory device includes a global bit line; a plurality of local bit lines connected to or disconnected from the global bit line via local bit line selection circuits which correspond to the local bit lines, respectively; and a plurality of phase-change memory cell groups storing data while being connected to the local bit lines, respectively. Each of the phase-change memory cells of each of the phase-change memory cell groups comprises a plurality of control transistors formed on different layers, and a variable resistance device formed of a phase-change material. In addition, the semiconductor memory device has a hierarchical bit line structure that uses a global bit line and local bit lines. Accordingly, it is …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.