High quality gallium oxide(Ga_2O_3) thin films are deposited by remote plasma-enhanced atomic layer deposition(RPEALD) with trimethylgallium(TMG) and oxygen plasma as precursors. By introducing in-situ NH3 plasma pret...High quality gallium oxide(Ga_2O_3) thin films are deposited by remote plasma-enhanced atomic layer deposition(RPEALD) with trimethylgallium(TMG) and oxygen plasma as precursors. By introducing in-situ NH3 plasma pretreatment on the substrates, the deposition rate of Ga_2O_3 films on Si and GaN are remarkably enhanced, reached to 0.53 and 0.46 ?/cycle at 250 °C,respectively. The increasing of deposition rate is attributed to more hydroxyls(–OH) generated on the substrate surfaces after NH3 pretreatment, which has no effect on the stoichiometry and surface morphology of the oxide films, but only modifies the surface states of substrates by enhancing reactive site density. Ga_2O_3 film deposited on GaN wafer is crystallized at 250 °C, with an epitaxial interface between Ga_2O_3 and GaN clearly observed. This is potentially very important for reducing the interface state density through high quality passivation.展开更多
In this work,we have successfully grown high quality epitaxialβ-Ga_(2)O_(3)thin films onβ-Ga_(2)O_(3)(100)and Al_(2)O_(3)(0001)substrates using pulsed laser deposition(PLD).By optimizing temperature and oxygen press...In this work,we have successfully grown high quality epitaxialβ-Ga_(2)O_(3)thin films onβ-Ga_(2)O_(3)(100)and Al_(2)O_(3)(0001)substrates using pulsed laser deposition(PLD).By optimizing temperature and oxygen pressure,the best conditions were found to be 650-700℃and 0.5 Pa.To further improve the quality of hetero-epitaxialβ-Ga_(2)O_(3),the sapphire substrates were pretreated for atomic terraced surface by chemical cleaning and high temperature annealing.From the optical transmittance measurements,the films grown at 600-750℃exhibit a clear absorption edge at deep ultraviolet region around 250-275 nm wavelength.High resolution transmission electron microscope(HRTEM)images and X-ray diffraction(XRD)patterns demonstrate thatβ-Ga_(2)O_(3)(-201)//Al_(2)O_(3)(0001)epitaxial texture dominated the epitaxial oxide films on sapphire substrate,which opens up the possibilities of high power electric devices.展开更多
基金supported jointly by the National Natural Science Foundation of China(Nos.61674165,61604167,61574160,61704183,61404159,11604366)the Natural Science Foundation of Jiangsu Province(Nos.BK20170432,BK20160397,BK20140394)+2 种基金the National Key R&D Program of China(No.2016YFB0401803)the Strategic Priority Re-search Program of the Chinese Academy of Science(No.XDA09020401)the support at the Platform for Characterization&Test,Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO),Chinese Academy of Sciences
文摘High quality gallium oxide(Ga_2O_3) thin films are deposited by remote plasma-enhanced atomic layer deposition(RPEALD) with trimethylgallium(TMG) and oxygen plasma as precursors. By introducing in-situ NH3 plasma pretreatment on the substrates, the deposition rate of Ga_2O_3 films on Si and GaN are remarkably enhanced, reached to 0.53 and 0.46 ?/cycle at 250 °C,respectively. The increasing of deposition rate is attributed to more hydroxyls(–OH) generated on the substrate surfaces after NH3 pretreatment, which has no effect on the stoichiometry and surface morphology of the oxide films, but only modifies the surface states of substrates by enhancing reactive site density. Ga_2O_3 film deposited on GaN wafer is crystallized at 250 °C, with an epitaxial interface between Ga_2O_3 and GaN clearly observed. This is potentially very important for reducing the interface state density through high quality passivation.
基金the National Natural Science Foundation of China(61674165,61604167,61574160,61704183,61404159,11604366)the Natural Science Foundation of Jiangsu Province(BK20170432,BK20160397,BK20140394)+2 种基金the National Key R&D Program of China(2016YFB0401803)the Strategic Priority Research Program of the Chinese Academy of Science(XDA09020401)XRD,AFM and TEM experiments were performed at the Platform for Characterization&Test,Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO),Chinese Academy of Sciences.
文摘In this work,we have successfully grown high quality epitaxialβ-Ga_(2)O_(3)thin films onβ-Ga_(2)O_(3)(100)and Al_(2)O_(3)(0001)substrates using pulsed laser deposition(PLD).By optimizing temperature and oxygen pressure,the best conditions were found to be 650-700℃and 0.5 Pa.To further improve the quality of hetero-epitaxialβ-Ga_(2)O_(3),the sapphire substrates were pretreated for atomic terraced surface by chemical cleaning and high temperature annealing.From the optical transmittance measurements,the films grown at 600-750℃exhibit a clear absorption edge at deep ultraviolet region around 250-275 nm wavelength.High resolution transmission electron microscope(HRTEM)images and X-ray diffraction(XRD)patterns demonstrate thatβ-Ga_(2)O_(3)(-201)//Al_(2)O_(3)(0001)epitaxial texture dominated the epitaxial oxide films on sapphire substrate,which opens up the possibilities of high power electric devices.
