Various Methods to Reduce Defect States in Tantalum Oxide Capacitors for DRAM Applications

2005 ◽  
Vol 864 ◽  
Author(s):  
W.S. Lau ◽  
G. Zhang ◽  
L.L. Leong ◽  
P.W. Qian ◽  
Taejoon Han ◽  
...  
Keyword(s):  
Leakage Current ◽  
Tantalum Oxide ◽  
Random Access ◽  
Defect States ◽  
Access Memory ◽  
Key Points ◽  
Type Semiconductor ◽  
O Vacancy ◽  
High Dielectric ◽  
Current Reduction

AbstractTantalum oxide has attracted world-wide interest for DRAM (dynamic random access memory) capacitor applications because of its relative high dielectric constant compared to silicon dioxide or nitride. We would like to point out that tantalum oxide behaves very much like a large bandgap n-type semiconductor with 3 main types of donors responsible for leakage current. Native oxygen vacancies are very deep double donors with Ec – Ed = 0.8 eV approximately, where Ec is the bottom of the conduction band and Ed is the energy leVel of the defect state. Si-O vacancy complexes are relatively shallow single donors with Ec – Ed = 0.2-0.4 eV. C-O vacancy complexes are relatively shallow single donors with Ec – Ed = 0.5-0.6 eV. The key points regarding how to suppress these 3 types of donor defects will be discussed for the purpose of leakage current reduction.

Hydrothermal synthesis of heteroepitaxial Pb(ZrxTi1−x)O3 thin films at 90–150 °C

1997 ◽  
Vol 12 (5) ◽  
pp. 1176-1178 ◽  
Author(s):  
A. T. Chien ◽  
J. S. Speck ◽  
F. F. Lange
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
High Dielectric Constant ◽  
Ambient Pressure ◽  
Random Access ◽  
Random Access Memory ◽  
Molar Ratio ◽  
Access Memory ◽  
Eds Analysis ◽  
High Dielectric

Pb(ZrxTi1−x)O3 and PbZrO3 heteroepitaxial thin films were produced in an aqueous solution (10 M KOH) at ambient pressure and low temperatures (90–150 °C) on (001) SrTiO3 and LaAlO3 single crystal substrates. Growth of the Pb(ZrxTi1−x)O3 and PbZrO3 thin films initiates by the formation of {100} faceted islands. Energy dispersive spectroscopy (EDS) analysis of the Pb(ZrxTi1−x)O3 thin film shows that the Zr: Ti ratio is 45: 56, nearly identical to the molar ratio of the precursors. This route might provide a viable low temperature alternative for the formation of high dielectric constant thin films for applications such as dynamic random access memory (DRAM).

scholarly journals KLECTOR: Design of Low Power Static Random-Access Memory Architecture with reduced Leakage Current

2021 ◽  
Author(s):  
Ananth Kumar Tamilarasan ◽  
Darwin Sundarapandi Edward ◽  
Arun Samuel Thankamony Sarasam
Keyword(s):  
Leakage Current ◽  
Random Access ◽  
Static Random Access Memory ◽  
Memory Architecture ◽  
Access Memory ◽  
Leakage Currents ◽  
Output Node ◽  
Voltage Drops ◽  
Novel Approach ◽  
Standby Mode

Abstract A novel approach called Keeper in LEakage Control Transistor (KLECTOR) is presented in this paper to reduce leakage currents in SRAM architecture. The SRAM is significantly affected by the leakage current during the "standby mode", which is caused by the fabric which has a lower threshold voltage. KLECTOR circuit employs less power consumption by restricting the flow of current through devices of less voltage drops and relies heavily on the self-controlled transistor at the output node. It has been found from the presented results that static (leakage) power in the write operation is reduced to 63% and 69 % for the read operation. This proposed approach is designed and simulated using the Virtuoso, Cadence EDA tool.

Hydrogen Permeation and Its Impacts on the Electrical Performance of Stacked ZrO2/Al2O3/ZrO2 Films

2020 ◽  
Vol 20 (11) ◽  
pp. 6638-6642
Author(s):  
Pyungho Choi ◽  
Youngseung Cho ◽  
Byoungdeog Choi
Keyword(s):  
Oxygen Vacancy ◽  
Leakage Current ◽  
Hydrogen Permeation ◽  
Random Access ◽  
Electrical Performance ◽  
Hydrogen Ions ◽  
Hydrogen Atoms ◽  
Access Memory ◽  
Conduction Electrons ◽  
Dielectric Capacitance

In this study, the effects of hydrogenation on the dielectric capacitance and leakage current of ZrO2/Al2O3/ZrO2 (ZAZ) films for dynamic-random-access memory (DRAM) capacitors were examined. Hydrogen permeation into ZAZ films reduced the dielectric capacitance and increased the leakage current with continued exposure to hydrogen during the forming gas annealing process. More specifically, the hydrogen ions distributed in the grain boundaries and at the Z/A interfaces appeared to disrupt the dipole motion and diminish the dielectric constant of the film, resulting in a decreased dielectric capacitance. Furthermore, the reaction of hydrogen atoms with the pre-existing oxygen of the ZrO2 films resulted in an oxygen vacancy with two captured electrons. Conduction electrons freed via ionization of the oxygen vacancy increased the conductivity of the ZAZ films, thereby increasing the leakage current throughout the ZAZ films.

Anomalous junction leakage current induced by STI dislocations and its impact on dynamic random access memory devices

1999 ◽  
Vol 46 (5) ◽  
pp. 940-946 ◽  
Author(s):  
Daewon Ha ◽  
Changhyun Cho ◽  
Dongwon Shin ◽  
Gwan-Hyeob Koh ◽  
Tae-Young Chung ◽  
...  
Keyword(s):  
Leakage Current ◽  
Random Access ◽  
Random Access Memory ◽  
Dynamic Random Access Memory ◽  
Memory Devices ◽  
Access Memory
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