Thermal reaction of polycrystalline AlN with XeF{sub 2}

Journal Article · Tue Nov 15 04:00:00 EST 2005 · Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films

DOI:https://doi.org/10.1116/1.2110395· OSTI ID:20723212

Watanabe, Morimichi; Mori, Yukimasa; Ishikawa, Takahiro; Sakai, Hiroaki; Iida, Takashi; Akiyama, Keijiro; Narita, Shogo; Sawabe, Kyoichi; Shobatake, Kosuke ^[1]

---

1. Materials Research Laboratory, NGK INSULATORS, LTD., 2-56 Suda-cho, Mizuho, Nagoya 467-8530 (Japan)

Detailed studies on the thermal reaction behavior of polycrystalline aluminum nitride (AlN) with effusive xenon difluoride (XeF{sub 2}) have been carried out over the sample temperature (T{sub s}) range from 300 to 920 K using molecular beam mass spectrometry combined with a time-of-flight technique and ex situ surface analyses, i.e., X-ray photoelectron spectroscopy, Auger electron spectroscopy, and scanning electron microscopy (SEM). The species desorbed from the AlN/XeF{sub 2} system were monitored using molecular beam mass spectrometry, as a function of sample temperature. Above T{sub s}=800 K, the desorbed reaction products were identified as N{sub 2} and AlF{sub 3}, and their flux intensities increase monotonically as the sample temperature is increased. The flux intensity of XeF{sub 2} desorbed after physisorption to the AlN surface is found to decrease as T{sub s} is raised above T{sub s}=800 K, and approximately one half of the incoming XeF{sub 2} is consumed by the thermal reaction at 920 K. The results of surface analyses show that the thermal reaction of AlN with XeF{sub 2} starts at approximately T{sub s}=700 K, forming a reaction layer composed of AlF{sub 3}. The AlF{sub 3} layer becomes thick as T{sub s} is increased from T{sub s}=700-800 K. Above T{sub s}=800 K, however, as a result of fast desorption of AlF{sub 3} and F atoms from the AlF{sub 3} layer, only partially fluorinated AlF{sub x} (x=1 and/or 2) layers are formed and the bulk AlN is revealed again. The SEM photographs indicate that the surfaces exposed above T{sub s}=850 K are strongly etched but a slight change is observed at T{sub s}{<=}800 K. On the basis of these results, three reaction stages are proposed for the AlN/XeF{sub 2} reaction depending on the sample temperature range: Stage 1 (300{<=}T{sub s}<700 K); no reaction, stage 2 (700{<=}T{sub s}<800 K); surface fluorination, and stage 3 (800{<=}T{sub s}); etching. At stage 3, AlF{sub 3} formed on the surface starts to evaporate and fast etching proceeds, since the vapor pressure of AlF{sub 3} is high enough in this temperature range.

• OSTI ID: 20723212
• Journal Information: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films Journal Issue: 6 Vol. 23; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADSORPTION
ALUMINIUM FLUORIDES
ALUMINIUM NITRIDES
AUGER ELECTRON SPECTROSCOPY
DESORPTION
ETCHING
FLUORINATION
LAYERS
MASS SPECTROSCOPY
MOLECULAR BEAMS
POLYCRYSTALS
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THERMAL ANALYSIS
TIME-OF-FLIGHT METHOD
VAPOR PRESSURE
X-RAY PHOTOELECTRON SPECTROSCOPY
XENON FLUORIDES