摘要:

A new gas phase pretreatment method was developed for blanket Al chemical vapor deposition (CVD) used in ultralarge‐scale integration metallization. This method uses a halogen‐free Ti compound. The pretreatment process involves exposing substrates to a tetrakisdimethylamino‐titanium atmosphere before the Al CVD. This significantly lowers the deposition temperature of CVD using dimethylaluminum‐hydride, and thus Al films can be deposited on SiO2even at 160 °C, where deposition would otherwise not occur. The deposited Al films have superior surface morphology due to higher Al island density in the early growth stage. Using this technique, V‐shaped trenches with an opening width of 0.4 μm and a depth of 1.2 μm are successfully filled with Al.

ISSN:0734-211X    

DOI:10.1116/1.588085

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

The preparation of epitaxial Au(111) films on mica by means of direct current magnetron sputtering is reported. We employed low‐energy electron diffraction, scanning electron microscopy, and scanning tunneling microscopy to study the surface structure of sputtered gold films at various deposition temperatures and substrate cleaning procedures. It will be shown that by sputter deposition at 400 °C onto oxygen annealed mica substrates uniformly textured gold films can be obtained which typically exhibit step‐free, atomically flat areas of about 150×150 nm2.

ISSN:0734-211X    

DOI:10.1116/1.588086

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

The friction and wear behavior of chemical vapor deposition grown diamond films has been investigated under strong ultrasound conditions at the friction interface. Experiments were performed on an alternating ‘‘pin‐on‐plate’’ tribometer constructed as an ultrasonic motor with excited bimodal mechanical vibrations at the frequency of 20 kHz. Ultrasound sliding of the films was done against alumina ceramics and with the diamond film itself. We have shown that chemical vapor deposition diamond films can be fast polished mechanically without significant graphitization by ultrasonic treatment. The initial film roughness was reduced from an averageRa≊3000 nm toRa≊10 nm. The polishing decreased the static coefficient of friction of the diamond film from about 0.53 to about 0.12. The operative mechanism for the polishing in the case of initially rough diamond samples appears to be asperity fracture. For smooth diamond samples it is suggested that tribochemical oxidation is also a polishing mechanism.

ISSN:0734-211X    

DOI:10.1116/1.588087

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

p‐type alloyed ohmic contacts of Au/Mn/Ni/Au have been fabricated for application to compound semiconductor devices. Extremely low resistance contacts to 3×1019cm−3Be‐dopedp‐GaAs were achieved by electron‐beam evaporation and rapid thermal annealing. Contacts were thermally stable, and the contact resistance remained below 0.04 Ω mm in the temperature range from 360 to 450 °C. Annealing at 400 °C for 40 s resulted in a minimum contact resistance of 0.012 Ω mm, corresponding to a specific resistivity of 1.6×10−8Ω cm2, which is very close to the theoretical predictions. The mechanism of formation of Au/Mn ohmic contacts was discussed, based on Auger electron spectroscopy data.

ISSN:0734-211X    

DOI:10.1116/1.588088

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

It has been reported that rapid thermal annealing of implanted (Be and Si) InSb at a temperature range of 300–450 °C for 20 s is sufficient to activate the implanted dopants. To investigate the effect of such annealing on the unimplanted parts of InSb, the electrical properties of Al and Ag/n‐InSb in which InSb is rapidly annealed (using proximity method) prior to Al and Ag evaporation are analyzed. It was determined that annealing at 300 and 350 °C does not degrade contact properties. The parameters of contacts considered here were barrier height (determined using capacitance–voltage method and current–voltage method) and ideality factor. For unannealed contacts the value of barrier height and ideality factor were found to vary in the range 0.14–0.17 eV and 1.12–1.31, respectively, depending on the metal type. Annealing at 400 °C slightly degraded the contact properties while annealing at 450 °C caused a significant degradation. The barrier height and ideality factor decreased to 0.1 eV and 1.41–1.52, respectively, when contacts are annealed at 450 °C. Creation of nonstoichiometric InSb surface layer and injection of charges into native oxide layer are likely causes for the contact degradation.

ISSN:0734-211X    

DOI:10.1116/1.588089

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

Ultrafine silicon quantum wires with high‐quality Si/SiO2heterointerfaces are successfully fabricated by utilizing anisotropic wet chemical etching and subsequent thermal oxidation. It is also found that the lateral dimensions of silicon quantum wires can be well controlled by selecting the temperature of the thermal oxidation process. The cross‐sectional image from a scanning electron microscope shows silicon quantum wires of high quality with the linewidth down to 20 nm.

ISSN:0734-211X    

DOI:10.1116/1.588090

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

The defects induced in the Si substrate by a CHF3/Ar plasma dry etch of SiO2on Si were studied by correlating the reactive ion etching (RIE) induced changes in the minority‐carrier bulk lifetime and surface recombination velocity with the data on damage obtained by the capacitance–voltage (C–V) and current–voltage (I–V) characteristics. Wet etched control samples were used to distinguish the defects induced by the processing in itself from the RIE‐induced defects. The influence of rf power was studied. No damage or contamination of the Si substrate was detected; a modification of the surface electric properties was observed in the samples etched at low rf power, and attributed to the presence of a residue layer.

ISSN:0734-211X    

DOI:10.1116/1.588091

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

In this paper we will review the performance of a ‘‘miniature’’ single pass cylindrical mirror analyzer (CMA) which we have used successfully in a variety of experiments. The underlying premise behind this CMA design was to minimize spatial requirements while maintaining an acceptable level of instrumental resolution. While we are presenting the results of a single pass cylindrical mirror analyzer, improvements on the present design, such as going to a double pass design, will undoubtedly improve the instrumental resolution.

ISSN:0734-211X    

DOI:10.1116/1.588092

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

A simple technique for creating trench structures in silicon using readily available wafer processing techniques is discussed. By using orientation dependent etching of (110) Si, it is possible to create trenches in silicon with vertical sidewalls. The etching anisotropy of certain solutions used with this technique is greater than 600:1 [110]:[111]etching, making it possible to fabricate virtually any value of aspect ratio trench. For this technique, which makes use of two etchants, an anisotropy of 50:1 is demonstrated. The equipment, materials, and processing steps required are outlined.

ISSN:0734-211X    

DOI:10.1116/1.588093

出版商:American Vacuum Society    

年代:1995

数据来源: AIP