Atomic Layer Deposition of AlN Thin Films on GaN and Electrical Properties in AlN/GaN Heterojunction Diodes

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

“…As native substrates of III-nitrides are hardly available (due to the difficulties with incorporating nitrogen), they are commonly grown on mismatched substrates involving thick buffer layers and high temperatures well above the back-end-of-line (BEOL) limit. , Atomic layer deposition (ALD) is a suitable candidate to investigate thin-film deposition of III-nitrides with a reduced thermal budget. In ALD, high conformality and large area uniformity with thickness control at a sub-monolayer scale are enabled by using sequential self-limiting vapor-solid reactions. ,− It has found use in numerous fabrication processes of devices and circuits with <10 nm feature sizes. − ,, Many authors have reported on ALD of Groups III–V (III–V) compounds since Nishizawa et al’s first paper on GaAs in 1985 (). ,, ALD of AlN commenced in the early 1990s with trimethylaluminum (TMA) as the metal precursor and ammonia (NH 3 ) as the nitrogen precursor. − Currently, a myriad of precursors, precursor combinations, and reactivity-enhancing techniques have been used to alter the ALD temperature window, limit the incorporation of impurities, and improve stoichiometry and crystallinity. Some authors using TMA as metal precursors have resorted to plasma-enhanced deposition to increase the reactivity of NH 3 at reduced temperatures. ,,,,− ,− One author has employed ultraviolet (UV) radiation during TMA injection...…”

High‐Temperature Stability Amorphous Ternary AlBN Dielectric Films on N++GaN

“…[ 1–4 ] For high‐electron‐mobility transistors, inserting a dielectric film under gate metal or depositing the passivation with dielectrics on the gate‐drain access region effectively reduces gate leakage, enlarges gate swing, and suppresses current collapse, which improve the device performance significantly. [ 5 ] Various binary metal oxide/nitride dielectrics, such as SiO 2 , [ 6 ] Si 3 N 4 , [ 7 ] Al 2 O 3 , [ 8 ] HfO 2 , [ 9 ] MgO, [ 10 ] Sc 2 O 3 , [ 11 ] Ta 2 O 5 , [ 12 ] ZrO 2 , [ 13 ] BN, [ 14,15 ] and AlN, [ 16,17 ] have been fabricated by physical or chemical vapor deposition methods. Although conventional SiO 2 , Si 3 N 4 , and Al 2 O 3 have good high‐temperature stability, their dielectric constant ( κ ) values are relatively low ( κ < 10).…”