Tris(dimethylamido)aluminum(III) and N2H4: Ideal precursors for the low-temperature deposition of large grain, oriented c-axis AlN on Si via atomic layer annealing

Experimental and theoretical determination of the role of ions in atomic layer annealing

“…AlN deposition conditions have been reported elsewhere. 19 Briefly, AlN deposition was conducted in a custom vacuum chamber (wall temp = 90 °C) with a base pressure < 1 × 10 −6 Torr and consisted of a home-built reactor pumped by a dry pump (Edwards EPX 500NE) protected by both a liquid nitrogen cold trap and stainless steel mesh particle trap (see Fig. S1, ESI†).…”

“…4,7 For many applications (e.g., surface or bulk acoustic wave devices [8][9][10][11] or heat spreaders [12][13][14] ), the deposition of crystalline films is required, which has led to the increasing adoption of a variant of ALD known as atomic layer annealing (ALA) as an alternative or supplement to conventional plasma enhanced ALD (PEALD). 7,[15][16][17][18][19] In the ALA process, either thermal ALD or PEALD is used to deposit the target material and low energy inert gas ions are used to bombard the surface. Using this ABCtype pulse sequence (reactant A, reactant B, and inert ions C), high-quality crystalline films can be deposited at low temperatures; however, the precise role of the inert ions in this process has thus far remained unclear.…”

Achieving a High Thermally Conductive One Micron AlN Deposition by High Power Impulse Magnetron Sputtering plus Kick

“…Depositing high-quality AlN films at lower temperatures has been studied most intensively through plasma techniques such as plasma-enhanced atomic layer deposition (PEALD) and sputtering to deposit polycrystalline structures with 10–100 nm grain size. ,− Sputtering techniques significantly decrease the temperature required for metallic or ceramic thin film crystallization due to the promotion of surface diffusion driven by energetic ions . While these methods have yielded thermal conductivity values for AlN of 130 W/m·K at around 1 μm thickness, the deposition techniques have challenges. ,− Perez et al demonstrated record high thermal conductivity with micron thickness AlN sputter-deposition; however, this conventional DC sputter with balanced magnetron configuration suffered from slow deposition rates. − ,,, The advanced high-power impulse magnetron sputtering (HiPIMS) has been utilized to create a reactive plasma with reduced hysteresis loops allowing for tighter control of operational point and enhanced the probability of reaction between nitrogen and gas phase aluminum in-between HiPIMS pulses, thereby enhancing the deposition rate. , Dense plasmas generated by HiPIMS also facilitate the growth of dense and smooth films . Bipolar HiPIMS, which combined HiPIMS and positive target bias, has been utilized in metal film deposition to further enhance surface diffusion during HiPIMS sputtering, which further densifies and smoothens films .…”

Area-Selective Low-Pressure Thermal Atomic Layer Deposition of Aluminum Nitride

“…Besides this classic set of precursors, other precursors and combinations have been introduced. Alternative nitrogen precursors are forming gas (N 2 + H 2 ), ,− hydrazine (N 2 H 4 ), − hydrazinium chloride (N 2 H 5 Cl), and monomethyl hydrazine (N 2 CH 6 ) . Alternative metal precursors are AlCl 3 , ,− TEA, , TMAA, , TDMAA, ,− DMEAA, − TDEAA, TiBA, and DMAA .…”

“…Alternative nitrogen precursors are forming gas (N 2 + H 2 ), ,− hydrazine (N 2 H 4 ), − hydrazinium chloride (N 2 H 5 Cl), and monomethyl hydrazine (N 2 CH 6 ) . Alternative metal precursors are AlCl 3 , ,− TEA, , TMAA, , TDMAA, ,− DMEAA, − TDEAA, TiBA, and DMAA . Additionally, metal precursors are being developed tailored to the ALD of AlN .…”