Very Thin Films of High Dielectric Constant Materials

1996 ◽  
Vol 446 ◽  
Author(s):  
David B. Beach ◽  
Catherine E. Vallet ◽  
Mariappan Paranthaman

AbstractAn all‐alkoxide route to SrBi2Ta2O9 (SBT) thin films and powders was developed. While stoichiometric gels transformed to single‐phase SBT, excess bismuth was required to obtain single‐phase SBT films on Pt substrates. An annealing temperature of 800 °C in O2 for 2 minutes was required to crystallize the films. Electrical measurements of SBT films produced under these conditions showed that films less than 2000 Å in thickness were shorted, while films of 3000 to 5000 Λ had a dielectric constant of~ 300. RBS measurements of a bismuth titanate film on Pt indicated that Pt diffuses into the dielectric layer when annealed at 700 °C in O2 for 1 minute, suggesting that interfacial reaction of these layered bismuth materials may be significant.

Author(s):  
Gyuseung Han ◽  
In Won Yeu ◽  
Kun Hee Ye ◽  
Seung-Cheol Lee ◽  
Cheol Seong Hwang ◽  
...  

Through DFT calculations, a Be0.25Mg0.75O superlattice having long apical Be–O bond length is proposed to have a high bandgap (>7.3 eV) and high dielectric constant (∼18) at room temperature and above.


2013 ◽  
Vol 22 ◽  
pp. 564-569
Author(s):  
KANTA RATHEE ◽  
B. P. MALIK

Down scaling of complementary metal oxide semiconductor transistors has put limitations on silicon dioxide to be used as an effective dielectric. It is necessary to replace the SiO 2 with a physically thicker layer of oxides of high dielectric constant. Thus high k dielectrics are used to suppress the existing challenges for CMOS scaling. Many new oxides are being evaluated as gate dielectrics such as Ta2O5 , HfO2 , ZrO2 , La2O3 , HfO2 , TiO2 , Al2O3 , Y2O3 etc but it was soon found that these oxides in many respects have inferior electronic properties to SiO2 . But the the choice alone of suitable metal oxide with high dielectric constant is not sufficient to overcome the scaling challenges. The various deposition techniques and the conditions under which the thin films are deposited plays important role in deciding the structural and electrical properties of the deposited films. This paper discusses in brief the various deposition conditions which are employed to improve the structural and electrical properties of the deposited films.


2018 ◽  
Vol 42 (13) ◽  
pp. 10969-10975
Author(s):  
Xuesong Wang ◽  
He Wang ◽  
Yao Li ◽  
Ting Xu ◽  
Wei Wang ◽  
...  

A polyurethane material with a high dielectric constant was used to regulate the grain size of p-6P.


2003 ◽  
Vol 768 ◽  
Author(s):  
Robert L. DeLeon ◽  
James F. Garvey ◽  
Gary S. Tompa ◽  
Richard Moore ◽  
Harry Efstathiadis

AbstractHigh dielectric constant (k), the thermal stability and the chemical stability with respect to reaction with silicon of hafnium oxide (HfO2), and zirconium oxide (ZrO2) places them among the leading candidates for an alternative gate dielectric material. High dielectric constant HfO2 and ZrO2 thin films have successfully been deposited on silicon substrates at a temperature of 27 °C by Laser Assisted Molecular Beam Deposition (LAMBD). The LAMBD process is related to conventional Pulsed Laser Deposition (PLD). In the PLD process, the ablation plume impinges directly upon the substrate to deposit the thin film, whereas in the LAMBD process, the ablation material is expanded within a concurrently pulsed stream of a reactive gas. The gas pulse serves both to create the desired material and to transport the material to the substrate for deposition of the thin film. One advantage of the LAMBD process is that a chemically reactive carrier gas can be selected to produce the desired chemical products. Depositions yielded 35 nm to 135 nm thick HfO2, and ZrO2 films.Structural and chemical characterization of the films were performed by Auger electron spectroscopy (AES), Rutherford back-scattering (RBS), scanning electron microscopy (SEM), and x-ray diffraction (XRD). Film surface was investigated by atomic force microscopy (AFM) while optical characterization was also performed by means of spectroscopic ellipsometry (SE). Within the process window investigated, the film Hf/O and Zr/O ratios was found to be in the range 0.6 to 1.2. The as deposited films were amorphous with refraction index (RI) at 623 nm wavelength films in the range of 1.22 to 1.27 for the HfO2 and in the range of 1.23 to 1.19 for the ZrO2 films.


Sign in / Sign up

Export Citation Format

Share Document