Characterization of Hafnium Oxide Thin Films by Source Gas Pulse Introduced Metalorganic Chemical Vapor Deposition Using Amino-Family Hf Precursors

Abstract

We have characterized hafnium oxide thin films grown on SiO 2 /p-Si(001) by source gas pulse introduced metalorganic chemical vapor deposition (MOCVD) using tetrakis-diethylamido-hafnium (Hf[N(C 2 H 5 ) 2 ] 4 ) and tetrakis-dimethylamidohafnium (Hf[N(CH 3 ) 2 ] 4 ). O 2 or H 2 O is used as oxidant gas. It is demonstrated that the use of H 2 O can reduce the residual impurity concentrations of hafnium oxide films when the deposition temperature is as low as 280 C. In addition, we have found that the residual impurity concentration of hafnium oxide films grown with Hf[N(C 2 H 5 ) 2 ] 4 is lower than that grown with Hf[N(CH 3 ) 2 ] 4 . This tendency agrees with the leakage current density. An equivalent SiO 2 thickness (EOT) of 1.4 nm with 4:7 Â 10 À6 A/cm 2 @-1 V have been obtained for the hafnium oxide films grown with Hf[N(C 2 H 5 ) 2 ] 4 at 280 C.

HfO2 and Hf1–xSixO2 Thin Films Grown by Metal‐Organic CVD Using Tetrakis(diethylamido)hafnium

“…[38,39] 4 Liquid 90°C / 6.5 Torr Hf(acac) 4 Solid 82°C/ 0.001 Torr (sublimation) Hf(NMe 2 ) 4 Solid 48°C / 0.1 Torr Hf(N(MeEt)) 4 Liquid 83°C/0.1 Torr Hf(NEt 2 ) 4 Liquid 110°C/ 0.1 Torr used as a CVD precursor. [28,29,40] However, it can produce polymeric derivatives. [15] A source that is both liquid and stable at room temperature can be obtained by substituting C 2 H 5 for CH 3 in the molecule, [15,16] and tetrakis(diethylamido)hafnium (Hf(N(C 2 H 5 ) 2 ) 4 ; H(NEt 2 ) 4 ) and tetrakis(ethylmethylamido)hafnium (Hf(N(C 2 H 5 )(CH 3 )) 4 ; H(NEtMe) 4 ) are considered as being novel precursors for metal-organic (MO)CVD.…”

Radiation Tolerance and Charge Trapping Enhancement of ALD HfO2/Al2O3 Nanolaminated Dielectrics

“…In fact, some recent investigations [ 38 ] notice that the incorporation of aluminum in ALD HfO 2 films significantly increases the density of oxygen vacancies. Another important aspect of the ALD films is the inevitable presence of hydrogen and C-N radicals as leftovers from the chemical reactions [ 39 , 40 ]. Their interaction with the annealing gas ambient could lead to creation of different types of defects depending on the used PDA environment.…”

Deposition of HfO2 Films by Liquid Injection MOCVD Using a New Monomeric Alkoxide Precursor, [Hf(dmop)4]

“…The 13 C 100.6 MHz). Thin film XRD data for the oxide films was obtained using nickel filtered Cu Ka radiation (k = 1.5405 ) with a 2h increment of 0.2. AES was carried out on a Jeol JAMP 7100 Auger spectrometer.…”

“…The metal nitrate complex [Hf(NO 3 ) 4 ] has been used for the MOCVD of high purity HfO 2 at low growth temperatures, [12] but anhydrous metal nitrate complexes are hazardous, highly reactive oxidants. Metal alkylamide complexes, such as [Hf(NMe 2 ) 4 ] [13,14] and [Hf(NEt 2 ) 4 ], [13] have also been used for the MOCVD of HfO 2 , but they are highly air-sensitive, and varying amounts of residual nitrogen and carbon can be incorporated in the oxide film. Metal alkoxides are attractive MOCVD precursors as they allow low deposition temperatures, and under optimum growth conditions, the deposition of low carbon-content films (<1 at.-% as measured by X-ray photoelectron spectroscopy (XPS)).…”