摘要:

We present here the selective molecular‐beam epitaxy (MBE) techniques used to achieve high quality material that integrates multiple device technologies on the same GaAs or InP substrate. We have successfully demonstrated selective MBE for both GaAs‐based high electron mobility transistor (HEMT)—heterojunction bipolar transistor (HBT) integration and InP‐basedPINdiode—HEMT integration. New merged processing technologies have been developed to achieve high performance monolithic microwave and optoelectronic HEMT‐HBT andPIN‐HEMT integrated circuits. In each case the performance potential of discrete devices has been maintained throughout the monolithic integration process.

ISSN:1071-1023    

DOI:10.1116/1.588160

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

We have fabricated pseudomorphic InGaAs–InAlAs–InP high electron mobility transistors by molecular beam epitaxy with InxGa1−xAs channels graded fromx=0.60 tox=0.80. Compared with device profiles using flatx=0.80 channels the channel conductivity is improved by 24%. Hall mobility is improved from 10 750 to 12 200 cm2/V s at 295 K with sheet charge Ns of 3.6×1012and 3.9×1012cm−2for the flatx=0.80 and graded‐channel profiles, respectively. Graded‐channel devices with 0.1 μmTgates obtained cutoff frequencyfT=305 GHz and maximum frequency of oscillationfmax=340 GHz.

ISSN:1071-1023    

DOI:10.1116/1.588161

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

X‐ray diffraction and glancing angle‐of‐incidence x‐ray reflectivity are applied to the analysis of AlGaAs–InGaAs–GaAs pseudomorphic high‐electron‐mobility transistor structures. Through comparisons between simulations and measured data, we are able to determine the InAs mole fraction and thickness of the InGaAs channel with precisions of ±0.003 and ±3 Å, respectively. The period of the AlGaAs/GaAs superlattice buffer, and the combined thickness of the AlGaAs gate and GaAs contact layers are determined with a precision of ±2%. Thickness values determined with these x‐ray techniques agree with those determined by transmission electron microscopy to within 6%.

ISSN:1071-1023    

DOI:10.1116/1.588162

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

We report the growth of high quality InSbp‐i‐nstructures which have been optimized using reflection high energy electron diffraction. Optimized InSbp‐i‐nstructures of 5.8 μm thickness demonstrated x‐ray full widths at half‐maximums (FWHMs) of 101 and 147 arcsec for GaAs and Si substrates, respectively, and exhibited excellent uniformity and morphology. Prototype InSbp‐i‐ndetectors on Si have been fabricated and have demonstrated photovoltaic response at 6.5 μm up to 200 K. A 4.8 μm InSb layer grown on GaAs at a growth temperature of 395 °C and a III/V incorporation ratio of 1/1.2 had an x‐ray rocking curve FWHM of 158 arcsec and a Hall mobility of 92 300 cm2 V−1 s−1at 77 K.

ISSN:1071-1023    

DOI:10.1116/1.588163

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

In this experiment the ultrahigh vacuum environment of a molecular‐beam epitaxy reactor equipped with ammonia was used to thermally nitride silicon. The resulting thin silicon nitride films were incorporated as gate insulators of metal‐insulator‐semiconductor field‐effect transistors. The fabrication of field‐effect transistors enabled very accurate interface state characterization of the silicon–silicon nitride interface by the charge pumping technique. The ammonia nitridation of silicon was also investigated as a surface passivation technique for scanning probe microscope (both conductive tip atomic force microscope and scanning tunneling microscope) lithography techniques.

ISSN:1071-1023    

DOI:10.1116/1.587888

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

Crystalline SiC thin layers have been grown on 125 mm silicon‐on‐insulator (SOI) substrates as a promising and economical substrate for the growth of GaN epilayers. Through the use of an AlN/GaN strained superlattice buffer layer, high quality GaN layers as thin as 2000 Å on Si(111) substrates have been achieved. X‐ray diffraction curves with a full width at half‐maximum (FWHM) as narrow as 25 arcmin were obtained. The associated low‐temperature photoluminescence (PL) spectrum showed a dominant bound‐exciton peak with a FWHM of 8 meV. We have further combined these two techniques to synthesize the first GaN on SiC on a SOI structure.

ISSN:1071-1023    

DOI:10.1116/1.587889

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

A sample bias on the order of −15 V arises during electron cyclotron resonance plasma‐assisted epitaxy of GaN on insulating substrates. In contrast, conducting substrates enable growth under zero or positive bias conditions. Surface morphology of GaN/Si(111) is progressively smoother with increasing bias (−10 to +10 V) for a microwave power of 30 W. Emission spectroscopy of the plasma suggests that both N and N+2are produced from collisions involving N*2and that for low power (10 W), the N and N+2production is limited by the N*2abundance. In contrast, at higher power (50 W), ion and atom production appears limited by the electron collision frequency. Electrostatic probe measurements near the growth stage indicate that the ion energy has a minimum of about 6 eV, attained at low plasma power or at medium power (30 W) with a positive substrate bias. Mg‐doped films produced at 10 W and zero bias are highly resistive.p‐njunction diodes formed by Si‐doped GaN grown on Mg‐doped GaN onp‐type Si are operated at relatively low current densities of 100 A cm−2and emit light near 2.5 eV at room temperature.

ISSN:1071-1023    

DOI:10.1116/1.587890

出版商:American Vacuum Society    

年代:1995

数据来源: AIP

摘要:

A new approach to expitaxial GaN growth using the plasma‐assisted ionized source beam epitaxy (PAISBE) is described. To facilitate the growth of GaN, an accelerated partially ionized Ga source beam was used along with an atomic nitrogen beam from an rf‐discharge nitrogen plasma. To control the amount of N+2ions leaving the discharge tube (thus participating in the GaN growth), a grid was installed at the exit end of the plasma tube. The growth parameters under control were the power and frequency of the rf discharge, the energy and fraction of ionization of the Ga beam, the Ga and N fluxes, and the substrate temperature. The crystal quality and surface morphology of the PAISBE‐grown GaN films on sapphire (0001) were analyzed using reflection high‐energy electron diffraction, x‐ray diffraction, and scanning electron microscopy. The best films were obtained with a partially ionized Ga beam at an rf power of 140 W, which exhibited a full width at half maximum of 25 min at the (0002) diffraction peak for a 0.4‐μm‐thick film. The buffer layer was a GaN film grown at 400 °C. Results illustrating the effects of various control parameters and, in particular, those demonstrating the advantages of PAISBE are presented.

ISSN:1071-1023    

DOI:10.1116/1.587891

出版商:American Vacuum Society    

年代:1995

数据来源: AIP