A Thermodynamic Analysis of Selective Area CVD of Titanium Nitride Compound by the Alternating Cyclic Method

Abstract

As the first step in investigating the selective area chemical vapor deposition of titanium compounds, which are of considerable interest in semiconductor technology, a thermodynamic analysis has been performed for the selective area chemical vapor deposition of titanium nitride, over an extensive temperature, pressure, and composition range, using the alternating cyclic (A.C.) process. In this approach TiN deposition via the hydrogen reduction of TIC14 is followed cyclically by the etching of spurious nuclei from mask regions via an embedded disproportionation reaction. The thermodynamic calculations have been set up using a first principles analysis, and carried out via the computer program, SOLGASMIX, which is based on the minimization of the system's Gibbs free energy. The first principles constraining conditions and the equilibrium constant constraining equations have then been employed as integrity checks of the outputs of the computer program. In addition, using the first principles approach, solid-vapor solubility curves have been derived for the cases examined. These calculations have indicated that the selective deposition of TiN by this novel method is feasible and have defined the parameter space in which to conduct the selective area deposition in A.C. fashion.

Cu CVD from Copper(II) Hexafluoroacetylacetonate: I . A Cold Wall Reactor Design, Blanket Growth Rate, and Natural Selectivity

“…The authors are particularly indebted to Dr. C. K. Williams of MCNC for his invaluable assistance in setting up the laser system. Manuscript submitted Nov. 14, 1994; revised manuscript received June 28, 1995. This paper reflects a partial fulfillment of Y.D.C.…”

Selective Area Chemical Vapor Deposition of Si[sub 1−x]Ge[sub x] Thin Film Alloys by the Alternating Cyclic Method: Experimental Data: I. Deposition Parameters

“…In order to find a better parameter space in which lower composition of Ge might be obtained, extensive thermodynamic calculations were performed to study the effect of various processing parameters such as H/Cl ratio and Ar/H 2 ratio. [26][27][28][29][30][31][32] Figure 3 presents the calculated mole fraction of Ge in the deposited solid phase as a function of temperature, for a total system pressure of 2.5 Torr, and for H/Cl input ratios of 10, 20, 30, 40, and 50, which were actually employed during experimental deposition studies. This is equivalent to H 2 /(SiCl 4 ϩ GeCl 4 ) ratios of 200, 100, 50, and 25, respectively.…”

“…It requires one additional level of precise control and has the potential to affect the thermodynamics and kinetics of the deposition process, as well as the properties of the deposited film. 23,24 The AC technique, reported previously for tungsten, 25 silicon, [26][27][28][29] and TiN, 30 involves the use of an embedded disproportionation reaction, which is activated cyclically, for etching of spurious nuclei on the mask surface. It does not involve addition of a special etching agent such as HCl or Cl 2 .…”

MOCVD of Titanium Nitride from a New Precursor, Ti[N(CH3)C2H5]4

“…Two types of titanium compounds such as titanium tetrachloride (TiCl 4 ) and metal−organic based chemistry have been widely used for CVD of TiN. TiCl 4 -based TiN has shown remarkable step coverage even in submicron contacts with an aspect ratio of 7.0, as well as excellent film properties including barrier properties and electrical resistivities. − However, this inorganic chemistry for CVD TiN suffers from some severe drawbacks. Chlorine contamination in TiN films leads to serious corrosion in Al/Cu metallization.…”