摘要:

The physics and technology of a relatively new, short‐time, thermal processing technique, namely rapid isothermal processing (RIP), based on incoherent sources of light for the fabrication of semiconductor devices and circuits, are reviewed in this paper. Low‐cost, minimum overall thermal budget, low‐power consumption, and high throughput are some of the attractive features of RIP. The discussion of RIP, in the context of other thermal processes, history, operating principles, different types of RIP systems, various applications of RIP using single processing steps, and novel applications of RIP, includinginsituprocessing and multistep processing, is described in detail. Current trends are in the direction of RIP‐dominated silicon integrated circuit fabrication technology that can lead to the development of the most advanced three‐dimensional integrated circuits suitable for applications such as parallel processing and radiation hardening. RIP is not only a superior alternative to furnace processing, but it is also the only way to perform certain crucial steps in the processing of compound semiconductor devices such as high‐mobility transistors, resonant tunneling devices, and high‐efficiency solar cells. Development of more accurate temperature measurement techniques and theoretical studies of heat transfer and other fundamental processes are needed. Dedicated equipment designed for a specific task coupled withinsituprocessing capabilities will dominate the future direction of RIP.

ISSN:0021-8979    

DOI:10.1063/1.340176

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

We have made a systematic study of the gain and noise in superconductor‐insulator‐superconductor mixers employing Ta based, Nb based, and Pb‐alloy based tunnel junctions. These junctions displayed both weak and strong quantum effects at a signal frequency of 33 GHz. The effects of energy gap sharpness and subgap current were investigated and are quantitatively related to mixer performance. Detailed comparisons are made of the mixing results with the predictions of a three‐port model approximation to the Tucker theory. We have measured mixer performance with a novel test apparatus which is accurate enough to allow for the first quantitative tests of theoretical noise predictions. We find that the three‐port model of the Tucker theory underestimates the mixer noise temperature by a factor of about 2 for all of our mixers. In addition, predicted values of available mixer gain are in reasonable agreement with experiment when quantum effects are weak. However, as quantum effects become strong, the predicted available gain diverges to infinity, which is in sharp contrast to the experimental results. Predictions of coupled gain do not always show such divergences.

ISSN:0021-8979    

DOI:10.1063/1.341026

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

A modified Michelson interferometer is used to study the strain properties of piezoelectric and electrostrictive materials. For small displacement, a feedback loop is introduced to stabilize the system against the low‐frequency optical path‐length drifting and the system is capable of resolving displacements of the order of 10−3A˚. For the strain induced by domain switching, a dual‐channel signal detection scheme is used which automatically reads out the displacement of the sample. The effect on the measurement of the sample bonding to a substrate and other related problems are discussed.

ISSN:0021-8979    

DOI:10.1063/1.341027

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

Several Nd:YAP lasers were constructed which could be broadly tuned in the 1083‐nm region which includes the helium 23S‐23Ptransition, using a Lyot filter and thin, uncoated etalons within the laser cavity. 1 W of power could be extracted at 1083 nm through a 1% transmitting output coupler. This laser beam was used to optically pump metastable4He and3He 23Shelium atoms in a weak discharge cell, spin polarizing the metastable ensemble. In a3He cell the polarization is transferred to the nuclear spin system. A3He target cell at 0.3 Torr was polarized to 52% in a few minutes. We describe the application of this system to the design of polarized targets for experiments in nuclear physics.

ISSN:0021-8979    

DOI:10.1063/1.341028

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

The Rutherford backscattering technique has been used to determine the range parameters of Bi ions implanted into AZ111 photoresist film at energies from 10 to 400 keV. An overall good agreement is found between the experimental results and the theoretical predictions by Biersack, Ziegler, and Littmark. It is also observed that a variation in the implantation dose does not affect the projected range and range straggling results, despite the fact that chemical modification of the implanted polymer layer is detected. In addition, we find that a shallow implantation of the polymer film with Bi ions increases the temperature at which the photoresist starts to decompose. Finally, at 300 °C the implanted Bi atoms diffuse preferentially toward the bulk. For this temperature, two different diffusion coefficients are estimated, one for the damaged regionDd=1.2×10−5cm2/s and another for the bulkDb=1.2×10−14cm2/s.

ISSN:0021-8979    

DOI:10.1063/1.341029

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

The static properties of stripe geometry gain guided lasers have been analyzed using a model that unifies the Auger recombination and the energetic carrier leakage mechanisms. Theoretical results show that the Auger recombination and carrier leakage could modify the gain profile and the optical intensity distribution in the laser cavity significantly, and could account successfully for the difference in the threshold behavior observed experimentally between GaInAsP/InP and AlGaAs/GaAs lasers.

ISSN:0021-8979    

DOI:10.1063/1.341030

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

Emission spectra from a high‐current line plasma produced by means of a formed‐ferrite plasma source have been measured in the ultraviolet spectral region 225–400 nm with emphasis on the ambient gas pressure dependence. A long distance, linear plasma of 13 cm was produced in a test chamber filled with CF4, N2, and Ar gases at various pressures ranging from 760 down to 10−5Torr. The formed‐ferrite plasma source was driven by a 2‐&mgr;F capacitor bank charged at 15–25 kV. When the line plasma was created in a high vacuum of 10−5Torr, several emission lines caused by singly ionized atomic species such as FeII and NiII which originated from the ferrite material appeared in the shorter wavelength region near 250 nm. This finding implies possible generation of vacuum ultraviolet, extreme ultraviolet, and soft x‐ray photons based on the higher ionized atomic species by the formed‐ferrite plasma source operating in such a high vacuum.

ISSN:0021-8979    

DOI:10.1063/1.341031

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

Li+and N+ions were implanted into aliphatic polymethylmethacrylate (PMMA), polyvinylalcohol (PVA), and aromatic polyimide (PI) polycarbonate (PC) polymers in the energy range of 100–130 keV. Planar optical waveguides guiding between one and three modes were formed. For low implantation doses (≤ 1014ions/cm2), total waveguide loss values at &lgr;=633 nm were found to be less than 2 dB/cm. The changes in the refractive index were found to be very large (&Dgr;n≥0.05) in the case of PMMA and PVA. We interpret this change in refractive index as being due to the formation of aromatic compounds in the regions of electronic scattering.

ISSN:0021-8979    

DOI:10.1063/1.341032

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

A simple interferometric technique for the study of radiation induced transient heating is demonstrated for the specific case of a glass substrate irradiated with pulsed 193‐nm excimer laser radiation. The technique relies on the fact that the optical path length of (633 nm) probe laser light within the substrate is sensitive to heat‐induced changes in the refractive index and thickness of the substrate. Interference between probe laser reflections from the front and back surfaces of the substrate allows these optical path length changes to be deduced from measured changes in sample reflectance. The technique offers fast response and is shown to be nearly quantitative.

ISSN:0021-8979    

DOI:10.1063/1.341033

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

The effect of gas flow parallel and transverse to the optical path and of the volume of the laser tube on N2laser energy and pulse width was experimentally investigated. Energy enhancements of more than a factor of 2 are clearly seen in transverse flow as compared with parallel flow. Gas flowrate affects the energy more in lasers with a large volume. Pulse widths in lasers with transverse flow are shorter than those with parallel flow by about 2 ns. These results show that both the direction of gas flow and the volume of the laser tube are important parameters to adjust to increase energy and power.

ISSN:0021-8979    

DOI:10.1063/1.341011

出版商:AIP    

年代:1988

数据来源: AIP