Semiconductor memories
Patent Information
- Authority / Receiving Office
- US · United States
- Patent Type
- Applications(United States)
- Current Assignee / Owner
- HITACHI LTD
- Publication Date
- 2005-10-27
- Estimated Expiration
- Not applicable · inactive patent
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Abstract
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a semiconductor memory, especially a dynamic random access memory (DRAM), and more particularly, the present invention relates to a series of cell structures, arrangements, and activation schemes for high density, low power semiconductor memories.
[0003] 2. Description of the Background
[0004] A conventional DRAM memory cell, consisting of one transistor and one capacitor (referred to as a 1T-1C configuration), is commonly used as a semiconductor memory when high bit density is required. This technology has several drawbacks and faces serious complications as device dimensions are scaled smaller. Most notably, since the DRAM cell has no internal gain, a high capacitance element (˜30 fF) must be fabricated in each cell to store a charge large enough to be adequately detected. Therefore, complex capacitor structures and expensive materials must be used to build a device with adequate c...