High Density Capacitorless Dynamic Random Access Memory Cell with Quasi Silicon-on-Insulator Structure Based on Bulk Substrate

2010 ◽  
Vol 49 (4) ◽  
pp. 04DD03
Author(s):  
Poren Tang ◽  
Ru Huang ◽  
Dake Wu ◽  
Yilin Zhang ◽  
Yangyuan Wang
2021 ◽  
Vol 21 (8) ◽  
pp. 4216-4222
Author(s):  
Songyi Yoo ◽  
In-Man Kang ◽  
Sung-Jae Cho ◽  
Wookyung Sun ◽  
Hyungsoon Shin

A capacitorless one-transistor dynamic random-access memory cell with a polysilicon body (poly-Si 1T-DRAM) has a cost-effective fabrication process and allows a three-dimensional stacked architecture that increases the integration density of memory cells. Also, since this device uses grain boundaries (GBs) as a storage region, it can be operated as a memory cell even in a thin body device. GBs are important to the memory characteristics of poly-Si 1T-DRAM because the amount of trapped charge in the GBs determines the memory’s data state. In this paper, we report on a statistical analysis of the memory characteristics of poly-Si 1T-DRAM cells according to the number and location of GBs using TCAD simulation. As the number of GBs increases, the sensing margin and retention time of memory cells deteriorate due to increasing trapped electron charge. Also, “0” state current increases and memory performance degrades in cells where all GBs are adjacent to the source or drain junction side in a strong electric field. These results mean that in poly-Si 1T-DRAM design, the number and location of GBs in a channel should be considered for optimal memory performance.


2018 ◽  
Vol 18 (9) ◽  
pp. 5919-5924
Author(s):  
Hyungjin Kim ◽  
Sihyun Kim ◽  
Hyun-Min Kim ◽  
Kitae Lee ◽  
Sangwan Kim ◽  
...  

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 228
Author(s):  
Hyeonjeong Kim ◽  
Songyi Yoo ◽  
In-Man Kang ◽  
Seongjae Cho ◽  
Wookyung Sun ◽  
...  

Recently, one-transistor dynamic random-access memory (1T-DRAM) cells having a polysilicon body (poly-Si 1T-DRAM) have attracted attention as candidates to replace conventional one-transistor one-capacitor dynamic random-access memory (1T-1C DRAM). Poly-Si 1T-DRAM enables the cost-effective implementation of a silicon-on-insulator (SOI) structure and a three-dimensional (3D) stacked architecture for increasing integration density. However, studies on the transient characteristics of poly-Si 1T-DRAM are still lacking. In this paper, with TCAD simulation, we examine the differences between the memory mechanisms in poly-Si and silicon body 1T-DRAM. A silicon 1T-DRAM cell’s data state is determined by the number of holes stored in a floating body (FB), while a poly-Si 1T-DRAM cell’s state depends on the number of electrons trapped in its grain boundary (GB). This means that a poly-Si 1T-DRAM can perform memory operations by using GB as a storage region in thin body devices with a small FB area.


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