Synthesis and Characterization of Tungsten Nitrido Amido Guanidinato Complexes as Precursors for Chemical Vapor Deposition of WN_xC_y Thin Films

Abstract

Tungsten nitrido amido guanidinato complexes of the type WN(NR 2 )[(NR′) 2 C(NR 2 )] 2 (R = Me, Et ; R′ = iPr, Cy) were synthesized as precursors for aerosol-assisted chemical vapor deposition (AACVD) of WN x C y thin films. The reaction of tungsten nitrido amido complexes of the type WN(NR 2 ) 3 (R = Me, Et) with two equivalents of a carbodiimide R′N=C=NR′ (R′ = iPr, Cy) resulted in two insertions of a carbodiimide into W-N(amido) bonds, affording bis(guanidinato) amido nitrido

Synthesis and Characterization of Tungsten Amide Complexes for the Deposition of Tungsten Disulfide Thin Films

“…Among the all-nitrogen-bonded W precursors, weight losses in W(N t Bu) 2 [( i PrN) 2 CMe] 2 , W(N t Bu) 2 (NMe 2 )[( i PrN) 2 CNMe 2 ], W(N t Bu) 2 (H)[( i PrN) 2 CNMe 2 ], and WN(NMe 2 )[(N i Pr) 2 C(NMe 2 )] 2 appeared at 100–350, 105–370, 175–370, and 125–200 °C, respectively. 19 − 21 The amounts of residual mass were approximately 63, 10, 25, and 22%, respectively. 19 − 21 Unlike non-sublimate WN(NMe 2 )[(N i Pr) 2 C(NMe 2 )] 2 , W(N t Bu) 2 [( i PrN) 2 CMe] 2 , [( i PrN) 2 CNMe 2 ], and W(N t Bu) 2 (H)[( i PrN) 2 CNMe 2 ] were sublimed at 130 °C (1 mTorr), 100 °C (10 –3 mbar), and 100 °C (10 –3 mbar), respectively.…”

“… 19 − 21 The amounts of residual mass were approximately 63, 10, 25, and 22%, respectively. 19 − 21 Unlike non-sublimate WN(NMe 2 )[(N i Pr) 2 C(NMe 2 )] 2 , W(N t Bu) 2 [( i PrN) 2 CMe] 2 , [( i PrN) 2 CNMe 2 ], and W(N t Bu) 2 (H)[( i PrN) 2 CNMe 2 ] were sublimed at 130 °C (1 mTorr), 100 °C (10 –3 mbar), and 100 °C (10 –3 mbar), respectively. 19 − 21 Furthermore, W 2 (MeNCH 2 CH 2 NMe) 3 23 is a W complex in which the same ligand is bound but is a nonvolatile dimer.…”

“…Among the all-nitrogen-bonded W precursors, weight losses in W­(N t Bu) 2 [( i PrN) 2 CMe] 2 , W­(N t Bu) 2 (NMe 2 )­[( i PrN) 2 CNMe 2 ], W­(N t Bu) 2 (H)­[( i PrN) 2 CNMe 2 ], and WN­(NMe 2 )­[(N i Pr) 2 C­(NMe 2 )] 2 appeared at 100–350, 105–370, 175–370, and 125–200 °C, respectively. − The amounts of residual mass were approximately 63, 10, 25, and 22%, respectively. − Unlike non-sublimate WN­(NMe 2 )­[(N i Pr) 2 C­(NMe 2 )] 2 , W­(N t Bu) 2 [( i PrN) 2 CMe] 2 , [( i PrN) 2 CNMe 2 ], and W­(N t Bu) 2 (H)­[( i PrN) 2 CNMe 2 ] were sublimed at 130 °C (1 mTorr), 100 °C (10 –3 mbar), and 100 °C (10 –3 mbar), respectively. − Furthermore, W 2 (MeNCH 2 CH 2 NMe) 3 is a W complex in which the same ligand is bound but is a nonvolatile dimer. However, in the case of 1 and 2 , although the residual masses were rather high at 40 and 28%, respectively, the sublimation temperatures were significantly lower at 70 and 75 °C under 450 mTorr, respectively.…”

“…The ligands employed in allnitrogen-bound W precursors included nitride, imido, amido, g u a n i d i n a t o , a n d a m i d i n a t o m o i e t i e s . W - 21 and W 2 (NMe 2 ) 6 22 are previously reported nitrogen-bound W precursors. These precursors are either nonvolatile or volatile only at high temperatures (that is, >130 °C).…”

“…The ligands employed in all-nitrogen-bound W precursors included nitride, imido, amido, guanidinato, and amidinato moieties. W(N t Bu) 2 [( i PrN) 2 CMe] 2 , 19 W(N t Bu) 2 (NMe 2 )[( i PrN) 2 CNMe 2 ], 20 W(N t Bu) 2 (H)[( i PrN) 2 CNMe 2 ], 20 WN(NMe 2 )[(N i Pr) 2 C(NMe 2 )] 2 , 21 and W 2 (NMe 2 ) 6 22 are previously reported nitrogen-bound W precursors. These precursors are either nonvolatile or volatile only at high temperatures (that is, >130 °C).…”