Quantum transport in high mobility modulation doped Ga0.25In0.75As/InP quantum wells

We present a theoretical study of the effects from symmetric modulation of the envelop wave function on quantum transport in square quantum wells (QWs). Within the variational approach we obtain analytic expressions for the carrier distribution and their scattering in symmetric two-side doped square QWs. Roughness-induced scattering are found significantly weaker than those in the asymmetric one-side doped counterpart. Thus, we propose symmetric modulation of the wave function as an efficient method for enhancement of the roughness-limited QW mobility. Our theory is able to well reproduce the recent experimental data about low-temperature transport of electrons and holes in two-side doped square QWs, e.g., the mobility dependence on the channel width, which have not been explained so far.

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Development of III-Sb Technology for p-Channel MOSFETs

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156414500153 ◽

2014 ◽

Vol 23 (03n04) ◽

pp. 1450015 ◽

Cited By ~ 3

Author(s):

Andrew Greene ◽

Shailesh Madisetti ◽

Michael Yakimov ◽

Vadim Tokranov ◽

Serge Oktyabrsky

Keyword(s):

Quantum Wells ◽

Supply Voltage ◽

High Mobility ◽

Hole Mobility ◽

State Density ◽

Injection Velocity ◽

Oxide Interface ◽

Group Iii ◽

Multiple Challenges ◽

Activation Annealing

Alternative channel materials with superior transport properties over conventional silicon based systems are required for supply voltage scaling in CMOS circuits. Group III- Sb 's are a candidate for high mobility p-channel applications due to a low hole effective mass, large injection velocity in scaled devices and the ability to achieve enhanced hole mobility in strained quantum wells (QW). Multiple challenges in antimonide MOSFET development are assessed and developed technologies were implemented into p-channel MOSFET fabrication with a low thermal processing budget of 350°C. These challenges include growth of “bulk” GaSb and bi-axial compressively strained In x Ga 1-x Sb QW channels on lattice mismatched GaAs substrates, reduction of interface trap state density (Dit) at the III- Sb /high-k oxide interface and avoiding ion implanted source and drain contacts with high temperature activation annealing. A “self-aligned” single mask p-channel MOSFET fabrication process was developed on buried In 0.36 Ga 0.64 Sb QW channels using intermetallic source and drain contacts. The first “gate-last” MOSFET process on In 0.36 Ga 0.64 Sb QW channels with pre-grown epitaxial p++- GaSb contacts is demonstrated. InAs has been proven to be an excellent etch stop layer when using an optimized tetramethylammonium hydroxide (TMAH) etch of p++- GaSb to prevent InGaSb QW damage.

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Mid-Infrared Photodetector Using Self-Assembled InAs Quantum Dots Embedded in Modulation-Doped GaAs Quantum Wells

MRS Proceedings ◽

10.1557/proc-607-147 ◽

1999 ◽

Vol 607 ◽

Author(s):

Seung-Woong Lee ◽

Kazuhiko Hirakawa ◽

Yozo Shimada

Keyword(s):

Quantum Dots ◽

Quantum Wells ◽

High Mobility ◽

Normal Incidence ◽

Infrared Photodetector ◽

Inas Quantum Dots ◽

Operation Temperature ◽

Long Lifetime ◽

Quantum Dot Infrared Photodetector ◽

Self Assembled

AbstractWe have designed and fabricated a quantum dot infrared photodetector which utilizes lateral transport of photoexcited carriers in the modulation-doped A1GaAs/GaAs two-dimensional (2D) channels. A broad photocurrent signal has been observed in the photon energy range of 100–300 meV due to bound-to-continuum intersubband absorption of normal incidence radiation in the self-assembled InAs quantum dots. A peak responsivity was as high as 2.3 A/W. The high responsivity is realized mainly by a high mobility and a long lifetime of photoexcited carriers in the modulation-doped 2D channels. Furthermore, we found that this device has high operation temperature and very high photoconductive gain.

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