Oxygen and hydrogen profiles and electrical properties of unintentionally doped gallium nitride grown by hydride vapor phase epitaxy

Abstract

Commercially available hydride vapor phase epitaxy gallium nitride (GaN) is characterized with the aim to correlate the oxygen and hydrogen secondary ion mass spectrometry profiles of a GaN wafer with the electrical properties of the sample. A GaN layer model, including doping profile and mobility, is derived, utilizing electrical (capacitance–voltage, Hall), structural (high resolution X‐ray diffraction) and optical (polarized infrared spectroscopy) methods. Oxygen and hydrogen are easily incorporated during hydride vapor phase epitaxy growth of GaN. Oxygen is an n‐type dopant in GaN, whereas hydrogen may passivate some of the donors. Electrical and optical properties correlate with a low defect concentration top GaN layer and a high defect concentration GaN interlayer.

Prediction of multiband luminescence due to the gallium vacancy–oxygen defect complex in GaN

“…2 Oxygen also tends to be present in undoped GaN, which is natively n-type. 3 In most ntype GaN samples, a yellow luminescence (YL) feature that has a peak at about 2.1-2.3 eV has been widely observed regardless of the growth technique used, which varies from molecular beam epitaxy 2 (MBE) 4 , and metal-organic chemical vapor deposition (MOCVD) 5,6,7 to hydride vapor phase epitaxy (HVPE) 7,8,9 . In some samples, the YL is accompanied by a red luminescence (RL) 7,10 or a green luminescence (GL) 8,11 .The source of YL is the subject of an on-going debate in the literature.…”

Au‐Free Ohmic Contacts and Their Impact on Sub‐Contact Charge Carrier Concentration in AlGaN/GaN Heterostructures

“…[14] Also, the TiN formation at the GaN interface [14] creating N vacancies in the (Al)GaN below, [19] acting as donors if occupied by oxygen atoms, is attributed to the local increase of the carrier concentration n s . [16] Furthermore, the shape of the plotted n s in Figure 8 is inversely proportional to the contact resistance R c plotted in Figure 7 as well as to the total resistance R total of the test devices (Figure 5). Since R total is dominated by R c as discussed earlier, and n s and R total were measured on the same van der Pauw samples, the dependence of R total on the carrier concentration n s was evaluated and is shown in Figure 9.…”

“…[14] If oxygen from the GaN surface substitutes these vacancies, the region below the contacts consequently becomes heavily n-doped. [15,16] This leads to pinning of the Fermi level [12,17] and thus to sharp semiconductor band bending, [1,13,18] allowing current transport in form of quantum mechanical tunneling with a high probability (Figure 2). Hence, electrons can move from (Al)GaN to Ti as free carriers by field emission (quasi ohmic behavior), rather than thermionic emission (Schottky behavior).…”

Review—Opportunities in Single Event Effects in Radiation-Exposed SiC and GaN Power Electronics

“…In this direction, the equilibrium lattice spacing is 2.590267 Å. 84 The corresponding stress at points 1 and 2 can be estimated to be 1.12 and-2.34 GPa, assuming Young's modulus of GaN to be 300 GPa. It is important to note that these are built-in stresses and not inverse piezoelectric stress components that will be added during device operation.…”