摘要:

Preliminary results are presented of the growth of CdTe, HgTe and Hg1−xCdxTe layers withx‐values between 0.9 and 0.17 by molecular beam epitaxy (MBE). The growths were performed in a MBE system equipped with both binary (CdTe) and elemental Cd, Hg, and Te sources on (111) orientatedAfaced CdTe wafers. Growth of CdTe layers on (100) orientated GaAs and InP layers was also obtained.

ISSN:1071-1023    

DOI:10.1116/1.582789

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

Two dominant deep electron traps, named ME3 and ME6, in Si‐doped AlxGa1−xAs grown by MBE have been studied by Deep Level Transient Spectroscopy (DLTS) and photoluminescence measurements. The change of the two trap concentrations with growth conditions and alloy composition, and the effects of them on photoluminescence intensity are described. The ME3 concentration shows strong alloy composition dependence and has a maximum nearly equal to the doping concentration atxof about 0.4. The ME3 concentration depends linearly on the doping concentration. The ME6 concentration depends strongly on the growth temperature above 720 °C. Group V/III beam flux ratio dependence of ME6 is less than the growth temperature dependence. The growth temperature and beam flux ratio dependences of ME3 are opposite to those of ME6. ME3 has no effect on photoluminescence intensity at room temperature, whereas ME6 reduces the photoluminescence intensity.

ISSN:1071-1023    

DOI:10.1116/1.582790

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

ISSN:1071-1023    

DOI:10.1116/1.582791

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The band bending on GaAs(001) surfaces prepared by molecular beam epitaxy (MBE) have been studied forn‐ andp‐type materials. Surfaces withc(4×4),c(2×8), and (4×6) reconstruction ranging from As to Ga rich have been investigated. The surface symmetry was determined by reflection high energy electron diffraction (RHEED) and the position of the valence band maximum relative to the Fermi level was measured using angle resolved UV photoelectron spectroscopy (ARUPS) at normal emission. The position of the Fermi level relative to the valence band maximum was found to be ∼0.7 eV forn‐type and ∼0.5 eV forp‐type material, with a slightly increasing trend in going from Ga‐ to As‐rich surfaces. For the (4×6) reconstructedn‐type samples the growth termination method was found to have a significant influence on the band bending. The results obtained here are in very good agreement with previous measurements of the Al–GaAs(001) Schottky barrier height indicating that the electronic properties of this junction are determined by the properties of the semiconductor.

ISSN:1071-1023    

DOI:10.1116/1.582792

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

ISSN:1071-1023    

DOI:10.1116/1.582793

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

ISSN:1071-1023    

DOI:10.1116/1.582794

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

One uncontrolled parameter of MBE growth on GaAs is the orientation of the substrate. Typical material is oriented to within 1/2 ° of a low‐index bulk plane so that the resulting surface consists of a staircase with random terrace lengths and step heights. These steps are important since at room temperature they can orient epitaxial layers and at high temperatures the terrace lengths can be comparable to diffusion distances. Ordered step arrays can also be an important factor in the formation of the characteristic streaked RHEED pattern. We have measured the profiles of these streaks from different wafers with nominally GaAs(001) surfaces and have observed striking differences which we ascribe to ordered staircase steps due to crystal misorientation. Misorientations as small as 1 mrad have been found. Surfaces in which the misorientation from the (001) was about 6.5 mrad were studied extensively and a reciprocal lattice was constructed from a map of the diffracted intensity vs scattering angles. On surfaces misoriented by 1°, RHEED oscillations were found to be much weaker than on the 6.5 mrad surface. Differences in the oscillations when the beam was directed first down and then perpendicular to the staircase direction were also observed, but these cannot yet be separated from differences due to temperature and flux ratios.

ISSN:1071-1023    

DOI:10.1116/1.582795

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The difference between furnace annealing and infrared flash lamp annealing on the electrical properties of modulation‐doped GaAs/N–AlGaAs structures grown by MBE was observed. After furnace annealing at about 700 °C, the electron mobility at 77 K decreased drastically due to diffusion of Si impurity ions from the N–AlGaAs layer into the undoped GaAs layer. In contrast to this, the mobility remained at a high value using flash lamp annealing, offering an excellent alternative annealing method for modulation‐doped GaAs/N–AlGaAs structures.

ISSN:1071-1023    

DOI:10.1116/1.582796

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

We report results of the characterization of a high throughput 3 in. MBE system which we have used to fabricate high quality, uniform modulation‐doped field‐effect transistors (MODFET’s). MODFET threshold voltage of 14.6% and hence Nd2product uniformity of 11.3% standard deviation across a 3 in. MBE wafer was achieved. MODFET’s with 77 K mobility over 100 000 cm2/V s were fabricated. Silicon was used as then‐type dopant of the (Al,Ga)As/GaAs heterostructures. Successful calibration of the Si cell temperature resulted in controlled doping in the range 1014cm−3to mid‐1018cm−3in GaAs. AlxGa1−xAs (x≂0.3) was also doped successfully up to 2.5 ×1018cm−3. Doping and thickness uniformity of 2% for both (Al, Ga)As and GaAs over the central 2.5 in. of 3 in. substrates was achieved using substrate rotation.

ISSN:1071-1023    

DOI:10.1116/1.582797

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The effect of high temperature annealing on the properties of silicon‐doped GaAs/AlGaAs double heterostructure (DH) grown by molecular beam expitaxy (MBE) and its application to the fabrication of transverse junction stripe (TJS) lasers are reported. In spite of the amphoteric nature of Si, it was found that the high temperature annealing gave little influence on the electrical and optical quality of then‐type DH wafer. The TJS laser using Si‐doped GaAs/AlGaAs wafer has been oscillated cw at room temperature and exhibited low threshold current of 30 mA and high quantum efficiency of 60%.

ISSN:1071-1023    

DOI:10.1116/1.582798

出版商:American Vacuum Society    

年代:1984

数据来源: AIP