Growth of ferroelectric oxide films on n-GaN/c-sapphire structures

Abstract

High-quality (Pb, La)(Ti, Zr)O3 films were grown on n-GaN. The film thickness ranged from 0.5 to 5 μm. The material was prepared by a chemical solution method with compositions of 8/65/35 and 0/52/48. The films grown on GaN buffered with a thin layer of indium in oxide were highly textured and exhibited excellent ferroelectric properties with Pr=20–26 μC/cm2. A large field-induced birefringence of 0.025 was measured in the film with a composition of 8/65/35 under a field strength of 2×105 V/cm.

Structural and electrical properties of Pb(Zr,Ti)O3 grown on (0001) GaN using a double PbTiO3∕PbO bridge layer

“…Therefore, the XRD data strongly suggest that the PbTiO 3 / PbO seed layer influences the orientation and crystal structure of PZT films and promotes heterogeneous PZT nucleation on GaN. Moreover, the ͑011͒ orientation of PZT reported for PZT/GaN structures 8,14 has not been found in the PZT/ PbTiO 3 / PbO / GaN films. An XRD pole figure analysis was performed to investigate the in-plane epitaxial relationship between the PZT and GaN films.…”

“…Therefore, it is imperative to incorporate a bridge layer ͑as a nucleation or seed layer͒ between PZT and GaN, which can promote the crystallization of the perovskite-phase PZT films. Fuflyigin et al 8 reported the growth of highly ͑110͒-oriented films by employing indium tin oxide for ͑Pb, La͒͑Ti, Zr͒O 3 ͑PLZT͒ films on n-GaN / c-sapphire structures and Masuda et al 6 used MgO for Pb͑Zr, Ti͒O 3 on cubic GaN / GaAs structures to grow preferentially ͑100͒-oriented PZT films. In this letter, we report on the growth of highly ͑111͒-oriented PZT films on GaN͑0001͒ / c-sapphire by employing of a double PbTiO 3 / PbO bridge layer.…”

Growth of epitaxially twinned ferroelectric Bi3.25La0.75Ti3O12(028) thin film on GaN substrate

“…These are suitable for high speed devices and opto-electronic applications. However, there has been few reports on the growth of metal-ferroelectric-semiconductor (MFS) stacked thin films using GaN as a semiconductor substrate [12,13]. In this letter, we report in detail on the epitaxial growth and structural analysis of the BLT on a GaN(0 0 2)/Al 2 O 3 (0 0 0 6) substrate prepared by the pulsed laser deposition (PLD) technique.…”

Highly textured Pb(Zr0.3Ti0.7)O3 thin films on GaN/sapphire by metalorganic chemical vapor deposition

“…[26][27][28][29] To date, a variety of processing techniques including rf sputtering, pulsed laser deposition (PLD), and sol-gel have been successfully used to deposit PZT films on group III nitride semiconductors. 18,23,[25][26][27][28][29] However, for commercial-scale production of device-quality PZT thin films on GaN, a manufacturable metalorganic chemical vapor deposition (MOCVD) process must be developed, a technique that offers a number of advantages, including excellent film uniformity on large substrates, good compositional control, high deposition rate, and conformal deposition on three-dimensional (3D) structures. 30,31 Although there have been numerous reports on the deposition of PZT by MOCVD, the substrates are typically pure metals (e.g., Pt, Ru, and Ir) or conducting metal oxides [e.g., IrO 2 , RuO 2 , (La, Sr) CoO 3 , and SrRuO 3 ].…”

“…19,20 Recently, the integration of PZT on cubic and wurtzite GaN for potential applications in microwave power and optoelectronic devices, as well as metal-ferroelectric-semiconductor field effect transistor (MFSFET) devices, has been demonstrated. 18,[21][22][23][24][25][26] Moreover, due to multiple advantages of wide band gap GaN as a resonator material, the ferroelectric PZT/semiconductor GaN heterostructure is being explored in radio-frequency (rf) microelectromechanical systems (MEMS) devices for insertion in rf communication systems. [26][27][28][29] To date, a variety of processing techniques including rf sputtering, pulsed laser deposition (PLD), and sol-gel have been successfully used to deposit PZT films on group III nitride semiconductors.…”