摘要:

The spatial distribution of charge carriers in semiconducting structures can be derived from conductive properties. In this report silicon cantilevers with integrated tips and coated with boron‐doped chemical vapor deposited diamond have been used for the first time to establish electrically reliable point contacts on silicon. The relation between the applied force and the nanoindentation characteristics has been investigated in a range from 10 to 150 μN. The threshold value necessary to pierce the native oxide layer has been obtained and is found to depend on the peculiar coating of each tip. The data are correlated with the current–voltage characteristics of the contacts. The impedance of point contacts on homogeneously dopedp‐ andn‐type silicon with known resistivity has been measured and calibration curves have been plotted for nanospreading resistance probe measurements. It is found that only above the threshold for plastic deformation can useful electrical characterizations be performed.

ISSN:1071-1023    

DOI:10.1116/1.589129

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

In scanned probe microscopy the image is a combination of information from the sample and the tip. In order to reconstruct the true surface geometry, it is necessary to know the actual tip shape. It has been proposed that this shape may be reconstructed from images of ‘‘tip characterizer’’ artifacts of independently known shape. The requirements for this strategy—dimensional uncertainty and instability of the characterizer small compared to the tip size—are not trivial. An alternative is ‘‘blind reconstruction,’’ which requires no information about the characterizer geometry apart from that contained within its image, yet produces an outer bound on the tip shape which for appropriately chosen characterizers is a good approximation. With blind reconstruction dimensional instability of characterizers is less problematical, and characterizer measurability is no longer a constraint, so more complex distributed characterizer geometries may be advantageously employed. In situations where part of a characterizer has a known shape, blind reconstruction and the known‐characterizer method may be combined.

ISSN:1071-1023    

DOI:10.1116/1.589130

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

Sharp needles on the Si(111)7×7 and Si(100)2×1 surfaces are formed in a controlled manner by applying a sample biasVsranging from +5.0 to +10.0 V while keeping the scanning tunneling microscope (STM) tunneling current constant. The size of the needle‐shaped structure is 1–20 nm in height and 1–5 nm in diameter depending on the bias voltage and duration (1–30 s). The needle structures are utilized to counter image the scanning tip with an atomic resolution (needle formation and tip imaging=NFTI). The STM resolution for the Si(111)7×7 structure is evaluated in relation to the atomic structure of the scanning tip imaged by the NFTI method. When a bias voltage ofVs=−10.0 V is used, needle formation on the scanning tip is observed. The NFTI method gives us a conventional technique to modify and monitorinsituthe scanning tip of STM.

ISSN:1071-1023    

DOI:10.1116/1.589131

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

SnO2thin films have been grown by radio frequency reactive sputtering method in order to be used as a gas sensor. Subsequently Pt has been added to the SnO2films to increase the sensitivity to carbon monoxide gas. Two different substrates have been used: rough and mechanically polished alumina. The morphology of the film has been characterized by atomic force microscopy, whereas the chemical composition was analyzed by x‐ray photoemission spectromicroscopy. Pt:SnO2clusters with widths of 500–600 nm were observed on the rough alumina, whereas on the mechanically polished alumina, the Pt:SnO2film was smoother. X‐ray photoemission spectromicroscopy measurements show for Pt:SnO2films on rough alumina substrates different charging in different areas of the sample. The response curve to carbon monoxide is 30% higher for rough alumina.

ISSN:1071-1023    

DOI:10.1116/1.589132

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

Because scanning probe microscopes produce three‐dimensional data of almost any solid they have a strong potential as metrological tools. Results are presented from the first international intercomparison between four national metrology laboratories. On three‐dimensional calibration standards the mean deviations between instruments were typically<2% in thexdirection,<5% in theydirection, and<10% in thezdirection. Eight samples were circulated for roughness measurements and 19 roughness parameters were calculated for each image. In the range where the scanning probe microscope measurements overlapped with classical techniques (profilometers) the agreement was good. Also a gauge block of hardened steel (≊900 HV) with an array of Vickers indentations having diagonal lengths ranging from 3 to 60 μm was circulated and measured.

ISSN:1071-1023    

DOI:10.1116/1.589133

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

Thickness of silicon dioxide was measured by combined atomic force microscopy and nanoscopicC–Vspectroscopy. The spatial variation of the oxide thickness and dopant profile on the masked Si were directly imaged. The nanoscopicC–Vreveals the same trends as the macroscopicC–V. Shadowing effect of phosphorous ions during implantation was observed from dopant profile in masked Si substrates.

ISSN:1071-1023    

DOI:10.1116/1.589134

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

Atomic force microscopes are being used increasingly for process metrology. As a case study, the measurement by atomic force microscope of a soda lime glass optical disk patterned using optical lithography and reactive plasma etching is examined. The atomic force microscope used for this measurement has a highly accurate scanner system. TheX,Y, andZaxes are calibrated using laser interferometry. To determine the shape of the tip used a commercially available tip calibration artifact was imaged both before and after the measurement. The image was corrected for the tip shape using mathematical morphology. The value of the atomic force microscope measurement is defined to be the impacts of the metrology on the product or process. It is shown that the value of atomic force microscopy process metrology on an optical disk is increased by using an accurate scanner, tip characterization, and morphological image analysis; however, the cost per measurement is increased as well. In general, the characteristics of the metrology required depends on the specific manufacturing process being supported.

ISSN:1071-1023    

DOI:10.1116/1.589135

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

Kelvin probe force microscopy was applied to the characterization of Al0.3Ga0.7As/GaAs multilayer structures and Si‐pnstructures. The spatial resolution of Kelvin probe force microscopy measurement was investigated using cleaved Al0.3Ga0.7As/GaAs structures. A 40‐nm‐thick Al0.3Ga0.7As layer was resolved with potential difference of 15 mV. It was found that the measured potential is sensitive to the Al mole fraction for AlGaAs. Two‐dimensional delineation of Si‐pnstructures was successfully carried out on the topmost and the cleaved surfaces. A decrease of a depletion‐layer width with increasing the intensity of light illuminating the sample was observed. It was confirmed through investigating illumination effects on various kinds of structures that the measured Kelvin probe force microscopy potential reflects the surface band structure of the sample. A lateral impurity profile under the ion implantation mask was extracted from the two‐dimensional potential image obtained on the cleavedpnjunction by calibrating with the impurity concentration profile measured by the spreading resistance method.

ISSN:1071-1023    

DOI:10.1116/1.589136

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

In the nanometer resolution range, image formation in scanning tunneling microscopy and atomic force microscopy is essentially governed by the geometrical interaction between the specimen surface and the tip surface. This nonlinear process can be described by using the tools of mathematical morphology. In principle, if the tip shape is precisely known, an image restoration can be performed. In this article, the capabilities of a blind restoration procedure which needs neither a precise knowledge of the tip shape nor the use of a known test object are presented. The efficiency of the blind restoration is demonstrated on an experimental atomic force microscopy image of a DNA molecule obtained in the ‘‘tapping mode’’.

ISSN:1071-1023    

DOI:10.1116/1.589137

出版商:American Vacuum Society    

年代:1996

数据来源: AIP

摘要:

Scanning probe microscopy has proven to be an invaluable tool for the investigation of surface topography; however, the finite geometry of the imaging tip can often distort image data and complicate metrological investigations of surface features. Here, the derivation of a computational procedure for the estimation of the geometry of the scanning probe from the topographic image data alone is presented. The properties of the tip function extracted from such data permit an assessment of the sample‐related information content of an image. The technique is demonstrated by its application to simulated scanning probe microscopy image data, where its performance can be assessed, and by its application to experimental image data obtained from the scanning force microscope.

ISSN:1071-1023    

DOI:10.1116/1.589138

出版商:American Vacuum Society    

年代:1996

数据来源: AIP