Thermal study of an indium trisguanidinate as a possible indium nitride precursor

Tris-N,N,-dimethyl-N′,N″-diisopropylguanidinatoindium(III) has been investigated both as a chemical vapor deposition precursor and an atomic layer deposition precursor. Although deposition was satisfactory in both cases, each report showed some anomalies in the thermal stability of this compound, warrenting further investigation, which is reported herein. The compound was found to decompose to produce diisopropylcarbodiimide both by computational modeling and solution phase nuclear magnetic resonance characterization. The decomposition was shown to have an onset at approximately 120 °C and had a constant rate of decomposition from 150 to 180 °C. The ultimate decomposition product was suspected to be bisdimethylamido-N,N,-dimethyl-N′,N″-diisopropylguanidinato-indium(III), which appeared to be an intractable, nonvolatile polymer.