Barrier height modification in Au/Ti/n-GaAs devices with a $$\hbox {HfO}_{2}$$ HfO 2 interfacial layer formed by atomic layer deposition

Abstract

X-ray photoelectron spectroscopy has been carried out to characterize the surface of the hafnia (HfO 2) thin films grown on n-GaAs wafer by atomic layer deposition, and the surface morphology of the HfO 2 layer on GaAs has been analysed using atomic force microscopy. The barrier height (BH) values of 1.03 and 0.93 eV (300 K) for the Au/Ti/HfO 2 /n-GaAs structures with 3-and 5-nm HfO 2 interfacial layers, respectively, have been obtained from the I-V characteristics of the devices, which are higher than the value of 0.77 eV (300 K) for the Au/Ti/n-GaAs diode fabricated by us. Therefore, it can be said that the HfO 2 thin layer at the metal/GaAs interface can also be used for BH modification as a gate insulator in GaAs metal-oxide semiconductor (MOS) capacitors and MOS field-effect transistors. The ideality factor values have been calculated as 1.028 and 2.72 eV at 400 and 60 K; and as 1.04 and 2.58 eV at 400 and 60 K for the metal-insulating layer-semiconductor (MIS) devices with 3-and 5-nm interfacial layers, respectively. The bias-dependent BH values have been calculated for the devices by both Norde's method and Gaussian distribution (GD) of BHs at each sample temperature. At 320 K, the b (V) value at 0.70 V for a 3-nm MIS diode is about 1.08 eV from the b (V) vs. V curve determined by the GD, and about 0.99 eV at 0.58 V for a 5-nm MIS diode. It has been seen that these bias-dependent BH values are in close agreement with those obtained by Norde's method for the same bias voltage values.

Effect of measurement frequency on admittance characteristics in Al/p-Si structures with interfacial native oxide layer

“…A carrier concentration value of 1.82 x 10 14 cm -3 was calculated from this part of the C -2 -V curve from Eq. (5).…”

Effect of atomic-layer-deposited HfO2 thin-film interfacial layer on the electrical properties of Au/Ti/n-GaAs Schottky diode

“…Schottky contacts based on group III-V semiconductors have been appeared especially in high speed optoelectronic and electronic structures such as solar cells, field-effect transistors, high electron mobility transistors, diodes [3][4][5][6][7]. Schottky diodes (SDs) are the simplest MS contact devices [8][9][10][11][12][13] and so that the understanding of which has great technological importance in the electronics. At this point, since gallium arsenide (GaAs) is one of the most important materials for low-power and high-speed devices, a full understanding of the nature of the electrical characteristics of GaAs based SDs is essential for its application.…”

“…In general, in literature, we find that mainly two parameters of a Schottky diode, ideality factor (n) and barrier height (BH) were evaluated and their dependence on temperature and voltage were discussed [14][15][16][17][18]. Biber et al [12], Kahveci et al [11] and Karabulut [13] have obtained an approximate value of zero-bias barrier height (ΦB0) as around 0.76 eV at 300 K for Au/Ti/n-GaAs MS diode.…”

“…Applying this theory, n and BH can be determined. There are some literature works on HfO2/Si or HfO2/GaAs diodes [13,[63][64][65][66]. Gullu et all fabricated the In/HfO2/Si diode, and ΦB0 and n for the this type of diode were determined 0.79 eV and 4.22 at room temperature, respectively [63].…”

The origin of constant phase element in equivalent circuit of MIS (n) GaAs structures

“…It is well known that the high density of interface states prevent for a long time a fabrication of field effect devices based on III-V semiconductor compounds in 90s. However, since the beginning of the twenty-first century, renewed interest in such devices has been observed [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. It is associated with the development of new passivation technologies, the construction of new metal-insulator-semiconductor field effect transistors (MISFET), and a number of issues related to silicon device scaling [16][17][18].…”