Electrical And Materials Properties Of Aln/ Hfo_2 High-κ Stack With A Metal Gate

摘要

In this study, aluminum nitride (AlN) was grown by molecular layer deposition on HfO_2 that had been deposited on 200 mm Si (100) substrates. The A1N was grown on HfO_2 using sequential exposures of trimethyl-aluminum and ammonia (NH_3) in a batch vertical furnace. Excellent thickness uniformity on test wafers from the top of the furnace to the bottom of the furnace (across the furnace load) was obtained. The equivalent oxide thickness was 16.5-18.8 A for the AlN/HfO_2 stack on patterned device wafers with a molybdenum oxynitride metal gate with leakage current densities from low 10~(-5) to mid 10~(-6) A/cm~2 at threshold voltage minus one volt. There was no change in the work function with the A1N cap on HfO_2 with the MoN metal gate, even with a 1000 ℃ anneal.