2005 Fiscal Year Final Research Report Summary
Epitaxial growth of Lithium Niobate film for optical material in the future
| Project/Area Number |
16560671
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Reaction engineering/Process system
|
|---|
| Research Institution | Tokai University |
|---|
Principal Investigator |
AKIYAMA Yasunobu Tokai University, School of Engineering, Associate Professor, 工学部, 助教授 (10231846)
|
|---|
| Project Period (FY) |
2004 – 2005
|
| Keywords | CVD / Lithium Niobate / Polycrystal / Epitaxially growth / Film composition / Growth condituon |
|---|
| Research Abstract |
The film composition of polycrystalline Lithium Niobate (LiNbO_3) that was prepared on silicon substrate from Li (DPM) and Nb(OEt)_5 using a MOCVD method was analyzed by ICP-MS. At any growth temperature, the polycrystalline Lithium Niobate can grow in Li-rich conditions.
By feeding both precursors simultaneously, pure LiNbO_3 films were grown epitaxially on sapphire [006] with no polycrystal oxides under the Li-rich conditions (X_Gi=0.586 at 973K, and 0.515<X_Gi<0.638 at 1023K) compared to the stoichiometric composition (X_Si=0.5) where X_Gi=the mole concentration of lithium atoms/(mole concentration of lithium atoms+mole concentration of niobium atoms) in the feed gas and X_Si=the mole concentration of lithium atoms/(mole concentration of lithium atoms + mole concentration of niobium atoms) in the film. The compositions of the epitaxially grown LiNbO_3 film were analyzed accurately using ICP-MS. The X_Si of epitaxially grown LiNbO_3, which contains no polycrystal oxides by XRD analysis, ranged from 0.49 to 0.521. These compositions of LiNbO_3 grown epitaxially using MOCVD correspond to the compositions of the LiNbO_3 solid solution in the phase-diagram of Li-Nb composite oxide obtained for crystal growth from a molten solution. However, the epitaxially grown film, which composition is away from the stoichiometric composition, must contain a few polycrystal oxides and some crystal defects. Thus, the film (X_Si=0.5), which is epitaxially grown with good quality, must be grown under narrower operating condition than the window obtained by this study.
|
