Annealing behavior of open spaces in AlON films studied by monoenergetic positron beams

Abstract

The impact of nitridation on open spaces in thin AlON x films deposited by a reactive sputtering technique was studied by using monoenergetic positron beams. For AlON x films with x ¼ 0%-15%, positrons were found to annihilate from trapped states in open spaces, which coexist intrinsically in an amorphous structure with three different sizes. Nitrogen incorporation into the Al 2 O 3 film increased the size of the open spaces, and their density increased as the post-deposition annealing temperature increased. The effect of nitrogen incorporation, however, diminished at x ¼ 25%. The observed change in the network structure was associated with the formation of a stable amorphous structure, which we could relate to the electrical properties of AlON x /SiO 2 /Si gate stacks.

Mobility enhancement in recessed-gate AlGaN/GaN MOS-HFETs using an AlON gate insulator

“…34,35) Note that the recess-etched GaN (AlGaN) surfaces were exposed to nitrogen-based plasma at the initial stage of AlON deposition. Incorporating nitrogen into the Al-based oxide can stabilize its amorphous structure while preventing crystallization, 34,39) so relatively high post-deposition annealing at 800 °C was conducted to give the gate stacks good insulating and interface properties. Then, TiN electrodes were deposited by reactive sputtering and were patterned using conventional photolithography and etching techniques.…”

Simple way of finding Ba to Si deposition rate ratios for high photoresponsivity in BaSi2 films by Raman spectroscopy

“…Through this method, vacancy-type defects of various semiconductors (i.e., GaN, AlON x , CIGS) have been investigated. [22][23][24][25][26] Figure 1(a) shows the S parameters of BaSi 2 films grown at T S = 580 °C with various R Ba /R Si . We found that the optical properties changed markedly as R Ba /R Si values were varied, and the maximum photoresponsivity was achieved at R Ba /R Si = 2.2 for samples grown at T S = 580 °C, as shown in Fig.…”

Hafnium silicate gate dielectrics in GaN metal oxide semiconductor capacitors

“…[1][2][3][4] Inserting a dielectric layer in such as MOS structures has been found to result in low leakage currents and high breakdown strengths. Numerous gate dielectrics, including SiN, 2,5) SiO 2 , 3,[6][7][8][9][10] Al 2 O 3 , 4,[11][12][13][14][15][16][17][18] AlON, 19) ZrO 2 , 20,21) HfO 2 , 20,22) Si x N x -SiO 2 , 1) SiO 2 -HfO 2 , 8) Al 2 O 3 -HfO 2 , 23) and Al 2 O 3 -TiO 2 bilayers, 24) (Al, Si)O, 25) and Al 2 O 3 /SiO 2 laminate 26) (forming AlSiO x ) have been studied for use in MOS units, and films of these materials are typically deposited via chemical vapor deposition or atomic layer deposition (ALD). ALD is the optimal approach to fabricating conformal films on three-dimensional structures, which is required when producing vertical GaN devices.…”