Dielectric properties of electron-beam deposited Ga2O3 films

Abstract

We have fabricated high quality, dielectric Ga2O3 thin films. The films with thicknesses between 40 and 4000 Å were deposited by electron-beam evaporation using a single-crystal high purity Gd3Ga5O12 source. Metal-insulator-semiconductor (MIS) and metal-insulator-metal structures (MIM) were fabricated in order to determine dielectric properties, which were found to depend strongly on deposition conditions such as substrate temperature and oxygen pressure. We obtained excellent dielectric properties for films deposited at substrate temperatures of 40 °C with no excess oxygen and at 125 °C with an oxygen partial pressure of 2×10−4 Torr. Specific resistivities ρ and dc breakdown fields Em of up to 6×1013 Ω cm and 2.1 MV/cm, respectively, were measured. Static dielectric constants between 9.93 and 10.2 were determined for these films. Like in other dielectrics, the current transport mechanisms are found to be bulk rather than electrode controlled.

Anisotropy, phonon modes, and free charge carrier parameters in monoclinicβ-gallium oxide single crystals

“…Schmitz, Gassmann, and Franchy report static and high-frequency values from line shape analysis of electron energy loss spectroscopy data from β-Ga 2 O 3 films on metal substrates [26]. Values obtained previously for films agree well with our isotropic average [22,26,27], while previously reported isotropic DC values are slightly smaller [23,24,26]. Data from recent band structure calculations are included in Table IV and show some agreement with our results [25,28].…”

“…No report exists to our best knowledge which observes and describes coupling of phonon and free charge carrier modes. Few reports exist on theoretical prediction and experimental determination of static and high-frequency dielectric constants and their anisotropy [22][23][24][25][26][27][28]. Calculations predict effective mass parameters [7,8,[29][30][31], and few experiments were reported [32,33].…”

ALD and MOCVD of Ga2O3 Thin Films Using the New Ga Precursor Dimethylgallium Isopropoxide, Me2GaOiPr

“…[36] Ga-doped zinc oxide (ZnO:Ga, GZO) is a wellknown n-type TCO material. [37] Thin films of gallium oxide have been prepared by various methods: (radiofrequency) magnetron sputter deposition, [1][2][3][4]6,7,9,10,12,25,27] electron beam evaporation, [15][16][17]21] pulsed laser deposition, [26,28,30,33,34,36] laser ablation, [31] CVD, [38][39][40][41][42][43][44][45][46][47] ALD, [48][49][50][51][52] molecular beam epitaxy, [32,35] vapor phase epitaxy, [53] spray pyrolysis, [54,55] and sol-gel process. [5,13,23,24] Among these methods, CVD is considered very important because it can readily be employed in industrial processes.…”

“…[9][10][11][12][13] It is also used as a passivation or dielectric layer for GaAs, [14][15][16][17][18] GaN, [19,20] or SiGe, [21] sometimes in combination with Gd 2 O 3 , [21] and shows catalytic [22] and photocatalytic [23] properties. Doped with manganese, gallium oxide becomes a luminescent material for green light.…”

Growth and characterization of gallium oxide thin films by radiofrequency magnetron sputtering

“…Recently, transparent conductive oxide (TCO) as alternative to expensive ITO have focused much attention owing to the wide variety of possible applications such as optical windows [1,2], high temperature chemical gas sensor [3], and dielectric layer [4]. Gallium zinc oxide (GZO) thin films have shown high conductivity and transparent properties with figure of merit comparable to those of ITO materials [5].…”