摘要:

An algorithm for the identification of areas that do not necessarily represent the true sample surface in atomic force microscope images is presented. These areas describe regions of the surface which might not have made contact with the probe tip during a raster scan, giving data which should be deemed questionable. Through the identification of these questionable data points, a more accurate picture of the sample can be obtained. The procedure is applied to several atomic force microscope images for the improvement of sample images and for obtaining tip information. While the algorithm is applicable to all such images, its sensitivity to noise reflects shortcomings in the assumption made in deconvolution.

ISSN:1071-1023    

DOI:10.1116/1.589261

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

Scanning tunneling microscopy was employed to study Mo clustering and interaction with substrate on highly oriented pyrolytic graphite. Mo follows the island growth mode, and the Mo clusters are distributed uniformly on a graphite surface. Thermal effects promote the diffusion of edge atoms and result in smooth edge and shape changes of the clusters. The appearance of triangular Mo clusters reflects the metal-substrate interaction. Cluster diffusion on a graphite surface was observed and the value of the diffusion coefficient for small Mo clusters were estimated to be on the order of10−19cm2/sat room temperature. Cluster-induced electron scattering standing waves were observed on the graphite surface.

ISSN:1071-1023    

DOI:10.1116/1.589262

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

Vinylidenefluoride and tetrafluoroethylene copolymer powder was evaporated to grow a thin film of polyvinylidenefluoride on a Si wafer with the native oxide layer held at 80 °C in a vacuum of10−5Torr. Its initial growth process was studied with an atomic force microscope. Some features in the initial film growth stage at 0.2 to 6 nm in its thicknessdare: (1) “plateau” and “mountain” islands with the number density in the order of107cm−2grow with the coverage linearly increasing withd; (2) secondary plateau islands grow atd>2nm; (3) the height was 6, 25, and 1.5 nm for plateau, mountain, and secondary plateau islands, respectively, which was almost independent ofd. These are briefly discussed from the viewpoint of the crystallization of bulk polymer and from the thin film growth process.

ISSN:1071-1023    

DOI:10.1116/1.589263

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

Thin film interference effects on process latitude in an off-axis (quadrupole) illumination system are investigated with a bottom antireflective coating (ARC) or without the bottom ARC over SiO2substrate using an electrical linewidth measurement technique. Experimental results indicate that an off-axis illumination system can improve an increasing disadvantage in maximum depth-of-focus (DOF) range with increasing resist thickness if using a resist thickness corresponding to a top extreme along the swing curve on a sufficient bottom ARC compared with the standard illumination system. But more serious thin film interference such as the case without the bottom ARC provides less advantage in the maximum DOF range even when reducing resist thickness. It is also found that centered focus positions exhibit a trend to offset in the positive defocus direction with increasing resist thickness, even using a combination of the bottom ARC and the smaller incident angle of illumination light in an off-axis illumination system. The centered focus positions without the bottom ARC are found to show more pronounced swing curve-type behavior with an almost horizontal inclination than that with the bottom ARC.

ISSN:1071-1023    

DOI:10.1116/1.589264

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

The operation of a high power density magnetron source during sputtering of a copper target both in standard mode with argon as well as in self-sputtering mode without argon is discussed. Voltage–current characteristics of the source and light emission spectra were taken for various conditions of magnetron operation to understand the transition from standard to self-sputtering mode. A qualitative explanation of the ionization mechanism is offered based on the effect of electron temperature and density on the Maxwellian distribution of electron energy.

ISSN:1071-1023    

DOI:10.1116/1.589265

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

Silicon oxides were rf magnetron sputtered onp-type silicon wafers, and annealed in the temperature range from 700 to 1000 °C for furnace annealing and from 950 to 1050 °C for rapid thermal annealing. The annealed oxides in metal–oxide–semiconductor structures were stressed with a constant current. Stability was monitored by midgap voltage and interface states density. The optimum condition to achieve the best electrical stability was furnace annealing at about 900 °C. It gives the least value of generated interface states and trapped charge after the electrical stress. A close relation between positive charge trapping and interface states generation is observed.

ISSN:1071-1023    

DOI:10.1116/1.589266

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

In order to achieve the critical dimension control and selectivity requirements of submicron etching, industrial oxide etching tools are utilizing low pressure, high density plasma etching processes. At low pressures, the mean free path (1 cm at 5 mTorr) approaches the distance between the wafer and the chamber interior. This permits chemical interaction between the chamber and the wafer, since some of the gas species leaving the chamber interior can reach the wafer before undergoing further gas/gas collisions. The contribution from gas species leaving the wafer clamp is even greater, since the distance between the wafer edge and the clamp is smaller than the mean free path under all pressure conditions. This leads to the manufacturing problem that processing results become dependent on the previous thermal and chemical history of the chamber interior and the clamp. Results obtained using an Applied Materials high density plasma contact etcher will illustrate the generic nature of this history problem. The dependence of the etching performance on the chamber temperature and previous chamber oxygen cleans will be discussed. The manufacturing challenge is to reproducibly achieve acceptable processing results in systems where the contribution to the processing from the chamber is continuously varying. Not only must the current state of the etching tool be known, but the processes required to recover a baseline operating condition must be understood. It will be argued that this will require real time diagnostic control of the process. It is also suggested that the trend to low pressure systems may have been taken too far, and pressures in the 20–40 mTorr range might result in better process control in terms of reducing the chamber “history” effect. (This article summarizes an invited presentation given by McNevin at the 42nd Annual American Vacuum Society national meeting in the Plasma Science Division.)

ISSN:1071-1023    

DOI:10.1116/1.589267

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

The effects of addingH2orCBrF3toCl2plasma to control the pattern profile in polysilicon etching are studied using a magnetron reactive ion etching system. It is found that the sidewalls of patterns etched with pureCl2plasma at the pressure of 12 Pa are vertical or sloped depending on whether a radio frequency (rf) power of 600 W (0.77W/cm2) or 700 W (0.9W/cm2) is applied. By increasing the content ofH2, the angle of the sidewall taper of the pattern etched at 600 W rf power reaches 70°. AddingCBrF3makes it possible to adjust the slope of the sidewall over a range from 77° to 65° at a rf power of 700 W. These observed results are attributed to plasma polymerization.

ISSN:1071-1023    

DOI:10.1116/1.589268

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

Electron cyclotron resonance hydrogen plasma has been found effective in cleaning Si surfaces in a matter of minutes, with no substrate heating. Deep level transient spectroscopy measurements showed only a broad defect peak with relatively low concentration immediately after the plasma exposure. Subsequent thermal anneals reveal emergence of strong new defects that have apparently been latent until the thermal anneal treatment. After annealing at temperatures above 450 °C, several well-defined defect peaks with concentrations above 1×1013cm−3appear near the Si surface. These defect concentrations reach their maximum at an anneal temperature of 500 °C and reduce to negligible levels at 750 °C. Experiments on wafers of different oxygen concentrations show that these defects are unrelated to the presence of oxygen in Si.

ISSN:1071-1023    

DOI:10.1116/1.589269

出版商:American Vacuum Society    

年代:1997

数据来源: AIP

摘要:

The influence of plasma exposure at self-bias voltages less than 200 V on electrical characteristics ofAl/n-Sidiodes was examined. In particular, the influence of chemical cleaning on the electrical characteristics of plasma-exposed diodes was examined. In Ar,N2,andO2plasma exposure followed by postcleaning, the electrical characteristics were the same as that of a nonplasma-exposed diode. The postcleaning treatment removed the damage layer formed during plasma exposure. On the other hand, in the diodes exposed toH2andH2-containing plasma followed by the postcleaning treatment, the electrical characteristics was not improved by the postcleaning treatment: the Schottky barrier height increased. The H-incorporated zone was not removed by the postcleaning treatment.

ISSN:1071-1023    

DOI:10.1116/1.589270

出版商:American Vacuum Society    

年代:1997

数据来源: AIP