Applied Surface Science 54 (1992) 75-77
North-Holland applied
surface science
Reactive pulsed laser deposition of TiN
D. Craciun and V. Craciun
Institute of A tomic Physics, Bucharest, Romania
Received 27 May 1991; accepted for publication 31 May 1991
Pulsed laser radiation has been successfully employed for thin film titanium nitride deposition. A pure titarüum target was
reactively evaporated in a nitrogen atmosphere by a 4 J/cm 2, 20 ns KrF laser pulse. The properties of the thin deposited films are
studied.
1. Introduction
The excellent high-temperature stability, hard-
ness, corrosion resistance and electrical properties
provide TiN many applications from cutting tools
and aesthetic coatings to VLSI microelectronics
[I].
TiN films can be obtained by a large number of
different techniques such as physical vapor de-
position [2], ion implantation [3], chemical vapor
deposition [4], or laser treatment [5,6]. The most
widely used deposition methods are reactive
evaporation [7,8] and reactive sputtering [9,10]
whereby pure titanium is either evaporated or
sputtered in the presence of a certain nitrogen
pressure.
Recently, the pulsed laser evaporation tech-
nique has gained prominence in the fabrication of
new high-T c superconducting thin films [11,12].
In this paper, an application of this technique
for titanium nitride deposition is presented.
A pure titanium target is pulsed laser evaporat-
ed in a nitrogen atmosphere. Different investiga-
tion techniques have shown that the deposited
films consist of titanium mononitride [6,9,14,15].
2. Experimentai details
Titanium targets of 99.9% purity were ¢leaned
with alcohol, rinsed with deionized water, dried in
a nitrogen jet, and then immediately loaded into
the deposition system.
The vacuum chamber was evacuated down to
10 -» Torr, purged with nitrogen, evacuated again,
and then filled with 99.99% purity nitrogen. After
several trials, the nitrogen pressure was set in the 1
to 20 Torr range.
The target was oriented as usual for laser de-
position at an angle of 45 ° to the incident excimer
(KrF~ X = 248 nm) laser beam.
Laser fluences from 3 to 6 J/cm 2, at a repe-
tition rate of 20 Hz were used.
The evaporated material was deposited onto a
silicon substrate placed parallel and at a distance
of about 4 cm away from the target. Thin de-
posited films were examined first by an optical
microscope and then by a scanning electron mi-
croscope (SEM), also equipped with an energy
dispersive analysis system (EDAX).
The thickness and composition were de-
termined by Rutherford backscattering spec-
troscopy (RBS) using 3.1 MeV He + ions and a
detector angle of 165 °
The elemental and chemical composition of the
deposited films were investigated by X-ray photo-
electron spectroscopy (XPS) with a VG-ESCA-
LAß MK II spectrometer. The A1Ka X-ray line
was used as exciting radiation at a background
pressure of 4 × 10-1° Torr.
Because the surface of the investigated nitrides
partly consists of oxides or oxynitrides, an Ar +
0169-4332/92/$05.00 © 1992 - Elsevier Science Publishers B.V. All rights reserved