Optimization and characterization of LPCVD TiB2 for ULSI applications

Article abstract of DOI:10.1149/1.2085366

The chemical vapor deposition of TiB₂ from gaseous mixtures of TiCl₄, B₂H₆, and H₂ onto various substrates was studied. A thermodynamic analysis using the SOLGASMIX computer program indicated that at an input gas ratio corresponding to the stoichiometry of TiB₂, the amount of secondary-phase deposition would be considerably reduced compared to that of TiB₂. For nonstoichiometric input gas mixtures, other solid phases, including oxides and silicides, are expected to result from the reaction with substrates. Experimental depositions of films were carried out in a cold wall system over a broad range of temperatures, pressures, and input gas flow rates. X-ray diffraction and x-ray photoelectron spectroscopy data indicate that the as-deposited films are very fine grained polycrystalline or amorphous, and the films RTA-annealed above 900°C are crystalline TiB₂. Below 550°C, surface reactions are the dominant factor for the kinetics of TiB₂ deposition, while mass transport is a limiting step for deposition above 550°C. At higher temperatures the deposition rate increases linearly with flow rate and total pressure, suggesting the deposition mechanism is reactant limited. The B/Ti ratio determined via Auger electron spectroscopy approaches the stoichiometric value of two in higher temperature films, while the presence of excess boron and chlorine was detected for low-temperature films. Stoichiometric TiB₂ films were deposited over a wide range of input gas mixture B/B + Ti ratios ranging from 0.4 to 0.71. Depletion effects of input gas were observed at low flow rate and high pressure where the residence time of reactants is longer than 10 s.

Full text of DOI:10.1149/1.2085366

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).

Downloaded on 2015-03-14 to IP 138.251.14.35 address. Redistribution subject to ECS terms of use (see ecsdl.org/site/terms_use) unless CC License in place (see abstract).