摘要:

Based on dimensional analysis, a configuration of a microlens system for focusing an electron beam can be obtained by the dimensional scaling down from a conventional lens. An electrostatic microlens system consisting of two planar microsize apertures has been investigated. For this microlens, the spherical and chromatical aberrations, the astigmatism due to elliptic distortion, and the displacement due to misalignment have been calculated in detail. The resolution has been derived by a general formula, and thus has been evaluated numerically. The computational results have shown that the miniaturized microlens system proposed in the present article possesses remarkably small aberrations and ultrahigh resolution in the low voltage operation, and will be likely applicable for some practical uses.

ISSN:1071-1023    

DOI:10.1116/1.585886

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

The variation method of fractal analysis is used to determine the fractal dimension of a surface imaged with a scanning tunneling microscope. Using this technique, an estimate of the experimental uncertainty in the fractal dimension is obtained. The utility of this variation method is demonstrated by investigating the fractal behavior of a fractured carbon surface.

ISSN:1071-1023    

DOI:10.1116/1.585887

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

A new method is reported to produce atomically sharp protrusions by laser‐induced reactive quenching of blunt tungsten tips. The field emitter tips made of 1 mm diam tungsten wire were processed in a benzene bath by pulsed Ruby laser (λ=693.4 nm, pulse width=30 ns). Subsequent examination of such tips in field ion and field electron emission microscopes shows very sharp atomic protrusions formed on the tip apex. The glancing angle x‐ray diffraction studies of thin tungsten foils laser irradiated under identical conditions reveal the formation of tungsten carbide on the surface. The atomic protrusions on the tip, thought to arise due to carbon atoms, were found to be strongly bound to the surface as judged by the field evaporation voltage required to strip them off the surface. The experimental results are explained on the basis of a laser‐induced reactive quenching process at the tungsten/benzene interface.

ISSN:1071-1023    

DOI:10.1116/1.585888

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

We report the use of the atomic force microscope (AFM) for local measurements of photoresist thickness and for the detection of residual photoresist in semiconductor processing. By scraping the photoresist off a small portion of a sample with the AFM stylus, and then imaging a larger area at low force, we have been able to measure the depth of a residual, photoresist masking layer. In addition, the AFM has been used to qualitatively judge the efficiency of three common methods of removing photoresist: a hot acetone bath left the most residual photoresist, a commercial stripper left less, and an oxygen plasma etch left none under our test conditions.  

ISSN:1071-1023    

DOI:10.1116/1.585889

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

Magnetron reactive ion etching of GaAs was investigated for the first time in a SiCl4plasma as a function of process parameters such as pressure and power density. The etch rate of GaAs is found to be much faster than the figures reported for conventional (unmagnetized) reactive ion etching. Vertical sidewalls and smooth surface morphology were obtained under the reported experimental conditions. Schottky diodes were fabricated on etched samples to assess the extent of residual damage. The ideality factor and barrier height of the etched samples were found to be close to those of an unetched control sample. The results indicate that SiCl4magnetron etching has promise for use in GaAs device fabrication.

ISSN:1071-1023    

DOI:10.1116/1.585890

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

Low‐pressure chemical vapor deposited (LPCVD) tungsten has been deposited onto LPCVD grown and reactively sputtered titanium nitride (TiN) films. The x‐ray photoelectron spectroscopy depth profiles and the chemical analysis suggest that the chemical interaction of TiN with W and with the Si/SiO2substrates tends to be minimal.

ISSN:1071-1023    

DOI:10.1116/1.585891

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

Plasma enhanced deposition of silicon nitride films is shown to have less N–H bonds and provide better heat resistance using SiH4–N2than SiH4–NH3–N2plasmas at 100 °C. Properties of silicon nitride using SiH4–N2plasma are studied versus various deposition parameters such as radio frequency power, silane flow ratio, and deposition pressure. The experimental data indicate that the deposition process at 100 °C has a N2‐reaction‐controlled mechanism.

ISSN:1071-1023    

DOI:10.1116/1.585892

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

The contact resistance and thermal stability of NiGe(Au)W ohmic contacts are reported as a function of their Au content. The contact resistance, measured by the transmission line method, is found to decrease monotonically from a maximum of ∼0.8 Ω mm for the Au‐free NiGeW contacts, to less than 0.15 Ω mm for NiGe(Au)W containing ∼60 Å of Au. The low Au content contacts are also found to be more stable than their Au‐free counterparts when stressed at 400 °C for a number of hours. Possible mechanisms to explain these results are proposed.

ISSN:1071-1023    

DOI:10.1116/1.585893

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

ISSN:1071-1023    

DOI:10.1116/1.585894

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

ISSN:1071-1023    

DOI:10.1116/1.585895

出版商:American Vacuum Society    

年代:1992

数据来源: AIP