Adsorption, Desorption, and Reaction of a Gallium Nitride Precursor, (H₂GaNHNMe₂)₂, on HfO₂

Abstract

The adsorption, desorption, and reaction of a dimeric gallium nitride precursor, (H 2 -GaNHNMe 2 ) 2 , on amorphous HfO 2 are studied using TPD, AES, isothermal reaction spectroscopy (IRS), and temperature-programmed reaction (TPR). When dosed below 120 K, (H 2 GaNHNMe 2 ) 2 adsorbs and desorbs molecularly and TPD results are consistent with a phase-transition model involving a low-temperature phase (phase A) that transforms irreversibly, between 190 and 215 K in competition with desorption, to a slightly more stable phase (B). The IRS, TPR, and AES data show that the dimers dissociate to monomers during dosing at 355 K, that GaN starts to form at 550 K, and that film-forming reactions become fast at 575 K. The results are consistent with monomer N-N bond cleavage to form hydrides, H 2 GaNH and HGaNH, that eliminate hydrogen to produce GaN. The GaN films are examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

UHV Surface Chemistry of bis(ethylcyclopentadienyl)ruthenium, (C2H5C5H4)2Ru on an Oxide Substrate

“…The typical base pressure was 5.0 10 ±10 torr. The sample mounting was similar to that for the HfO 2 /Ni substrate reported previously [45]. The substrate can be cooled by liquid nitrogen to 110 K, and resistively heated to 1000 K.…”

“…7), described in detail elsewhere [44,45], is equipped with a TOFMS with a liquid N 2 -cooled copper tube at the entrance to suppress background signals, a line of sight dosing system, and a single-pass cylindrical mirror analyzer for AES. The greatest advantage of TOFMS is its ability to gather all mass data, in principle, without limit [46].…”

Reactions of Hydrazines with AlH3·NMe2Et – Formation of Aluminum‐Nitrogen Heterocycles

“…An almost colorless solution was obtained upon stirring of the reaction mixture overnight. Equation (1) gives the idealized stoichiometry of the reaction. Cooling to +3°C afforded colorless crystals of compound 1 in 64 % yield.…”

“…An unambiguous assignment of resonances to the chemically different phenyl groups succeeded only in the 13 C NMR spectrum. (1) The central structural motif of compound 1 is the fivemembered Al 2 N 3 heterocycle ( Figure 1). The Al-N distances in the heterocycle (182.6 to 186.2 pm) are relatively short compared to other hydrazides, which clearly is caused by the negative charges localized at each nitrogen atom and an increased ionic contribution to the bonding.…”

“…[1] (ii) The particular arrangement of lone pairs of electrons at two directly connected nitrogen atoms cause the formation of a broad variety of different and unprecedented structural motifs. [2] The reactions of organoaluminum, -gallium or -indium compounds with hydrazine derivatives gave simple adducts in the first step, which could be isolated and characterized in several cases.…”