Fabrication of high density ultrafine GaAs quantum wire array structures using selective metalorganic chemical vapor deposition

1992 ◽  
Vol 267 (1-3) ◽  
pp. 214-217 ◽  
Author(s):  
Shi Shya Chang ◽  
Seigo Ando ◽  
Takashi Fukui
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Wire ◽  
Metalorganic Chemical Vapor Deposition ◽  
Wire Array ◽  
Chemical Vapor ◽  
High Density ◽  
Array Structures ◽  
Metalorganic Chemical

Metalorganic chemical vapor deposition of very thin Pb(Zr,Ti)O3 thin films at low temperatures for high-density ferroelectric memory applications

2001 ◽  
Vol 16 (12) ◽  
pp. 3583-3591 ◽  
Author(s):  
Hye Ryoung Kim ◽  
Seehwa Jeong ◽  
Chung Bae Jeon ◽  
Oh Seong Kwon ◽  
Cheol Seong Hwang ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Ferroelectric Properties ◽  
Chemical Vapor ◽  
High Density ◽  
Pt Electrode ◽  
Ferroelectric Memory ◽  
Metalorganic Chemical

The metalorganic chemical vapor deposition of very thin (<50 nm) Pb(Zr,Ti)O3 (PZT) thin films was performed for high density (>32 mega bit) ferroelectric memory devices. The growth temperatures were set between 450 and 530 °C to obtain a smooth surface morphology and prevent damage to the underlying reaction barrier layer. The average grain size of a 50-nm-thick film on a Pt electrode was about 34 nm with a size distribution (σ2) of 11 nm. These values are much smaller than the sol-gel-derived PZT films (55 and 25 nm, respectively). Very thin films with a thickness of approximately 30 nm were prepared at wafer temperatures ranging from 500 to 525 °C. Even with the very small thickness, the films showed good ferroelectric properties with a typical remanent polarization from 10 to 15 μC/cm2 and an extremely low coercive voltage of 0.3 V. However, the leakage current density was rather high resulting in nonsaturating polarization versus voltage curves. Even though good ferroelectric properties were obtained, the formation of PtxPby alloys on top of the Pt electrode was consistently observed. This precludes the reliable control of film composition and electrical performance. The adoption of an Ir electrode successfully eliminated intermetallic alloy formation and resulted in better and reproducible process control. A 50-nm-thick PZT film on an Ir/IrO2/SiO2/Si substrate also showed a reasonable ferroelectric performance.

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