[go: up one dir, main page]

WO2010117467A2 - Transistor bipolaire doté d'une base à puits quantique et d'un émetteur à puits quantique - Google Patents

Transistor bipolaire doté d'une base à puits quantique et d'un émetteur à puits quantique Download PDF

Info

Publication number
WO2010117467A2
WO2010117467A2 PCT/US2010/001067 US2010001067W WO2010117467A2 WO 2010117467 A2 WO2010117467 A2 WO 2010117467A2 US 2010001067 W US2010001067 W US 2010001067W WO 2010117467 A2 WO2010117467 A2 WO 2010117467A2
Authority
WO
WIPO (PCT)
Prior art keywords
base
quantum well
emitter
bipolar transistor
collector
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2010/001067
Other languages
English (en)
Other versions
WO2010117467A3 (fr
Inventor
Samson Mil'shtein
Amey V. Churi
Peter N. Ersland
Brian J. Rizzi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Massachusetts Amherst
Original Assignee
University of Massachusetts Amherst
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Massachusetts Amherst filed Critical University of Massachusetts Amherst
Publication of WO2010117467A2 publication Critical patent/WO2010117467A2/fr
Publication of WO2010117467A3 publication Critical patent/WO2010117467A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D10/00—Bipolar junction transistors [BJT]
    • H10D10/80—Heterojunction BJTs
    • H10D10/821—Vertical heterojunction BJTs
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D62/00—Semiconductor bodies, or regions thereof, of devices having potential barriers
    • H10D62/10—Shapes, relative sizes or dispositions of the regions of the semiconductor bodies; Shapes of the semiconductor bodies
    • H10D62/117—Shapes of semiconductor bodies
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D62/00—Semiconductor bodies, or regions thereof, of devices having potential barriers
    • H10D62/10—Shapes, relative sizes or dispositions of the regions of the semiconductor bodies; Shapes of the semiconductor bodies
    • H10D62/13—Semiconductor regions connected to electrodes carrying current to be rectified, amplified or switched, e.g. source or drain regions
    • H10D62/133—Emitter regions of BJTs
    • H10D62/136—Emitter regions of BJTs of heterojunction BJTs 

Definitions

  • a bipolar junction transistor typically has three terminals: a base, an emitter, and a collector.
  • the main current of the transistor flows between the emitter and collector terminals.
  • the base is a control terminal that controls the flow of current between the emitter and the collector.
  • HBT Heteroj unction Bipolar Transistors
  • a quantum well is a potential well that can confine the wavefunction of carriers within a region.
  • a quantum well can be formed as a thin layer of material having a potential different from the adjacent layers. Combining a thin base with various heterostructures can allow a designer to leverage quantum effects to achieve favorable properties.
  • Resonant tunneling Bipolar Transistor having a double barrier and a quantum well in the base to form a negative transconductance device.
  • Bipolar Quantum Resonant Tunneling Transistor (BiQuaRTT) was developed, which has a quantum well base and two barriers at both junctions.
  • Narrow Base HBTs (NBHBT) have a reduced base thickness which lessens both the base transit time and the base recombination current, thus enhancing DC current gain.
  • the Bipolar Inversion Channel Field Effect Transistor is an example of a NBHBT which has a ⁇ of 10 5 and high current operation (10 6 A/cm 2 j.
  • This device has no base to limit scaling in the vertical dimension as with a bipolar transistor, and it has no drain to limit its scaling in the planar dimension as with a Field Effect Transistor (FET).
  • FET Field Effect Transistor
  • Another NBHBT proposed by K. Ikossi-Anastasiou et al. has a base thickness of just 50 A. This transistor exhibits a maximum small-signal common emitter current gain of 1400 at 300° K and 3000 at 80° K.
  • the Heterostructure Emitter and Heterostructure Base Transistor (HEHBT) with pseudomorphic base has a quantum well base of Ino .2 Gao .8 As enhancing the valence band discontinuity ( ⁇ Ev), which results in a higher emitter injection efficiency.
  • the device shows S-shaped negative differential resistance phenomena in the inverted operation mode.
  • Quantum well bases are also used for optoelectronic purposes.
  • M. Feng et al. reports enhanced radiative recombination realized by incorporating InGaAs quantum wells in the base layer of Light- Emitting InGaP/GaAs heteroj unction bipolar Transistors (LETs) operating in the common- emitter configuration.
  • LETs Light- Emitting InGaP/GaAs heteroj unction bipolar Transistors
  • Such devices simultaneously show both an amplified electrical output and an optical output with signal modulation.
  • a paper by A.C.Seabaugh Quantantum-well resonant tunneling transistors", Proceedings IEEE/Cornell Conference on Advanced Concepts in High Speed Semiconductor Devices and Circuits, p. 255 - 264, 1989 gives a summary of several kinds of resonant tunneling HBTs that have been developed.
  • the bipolar transistor may include an emitter that includes a first semiconductor region of a first conductivity type. The first semiconductor region has a small enough thickness to form a first quantum well.
  • the bipolar transistor may also include a collector that includes a second semiconductor region of the first conductivity type.
  • the bipolar transistor may further include a base comprising a third semiconductor region of a second conductivity type. The base is formed between the first semiconductor region and the second semiconductor region.
  • the third semiconductor region has small enough thickness to form a second quantum well.
  • the first quantum well is formed of a material of higher bandgap than the second quantum well.
  • the third semiconductor region is formed of a different semiconductor material than the first and second semiconductor regions.
  • the first and second semiconductor regions are formed of the same semiconductor material.
  • the first and second semiconductor regions comprise InGaP and the third semiconductor region comprises GaAs.
  • the first and second semiconductor regions have a first conductivity type and the third semiconductor region has a second conductivity type opposite to the first conductivity type.
  • the current gain of the transistor is better than in a corresponding HBT without a quantum well, wherein the HBT has an emitter, base and collector formed of the same materials as the bipolar transistor.
  • the first and second quantum wells significantly improve the breakdown voltage of the transistor.
  • FIG. 1 shows a cross section of a bipolar transistor according to one embodiment.
  • FIG. 2 shows a top-view image of the transistor of FIG. 1.
  • FIG. 3 shows a graph of I- V characteristics for the transistor of FIG. 1.
  • FIG. 4 shows a Gummel plot for the transistor of FIG. 1.
  • FIG. 5 shows a cross section of a bipolar transistor with a quantum well base.
  • FIG. 6 shows plots of the collector current versus collector voltage for various base current values of a commercially available hetrojunction bipolar transistor.
  • FIG. 7 shows plots of the collector current vs. collector voltage for various base current values of a quantum well base hetrojunction bipolar transistor.
  • FIG. 8 shows plots of the S 2 i parameter for the quantum well base hetrojunction bipolar transistor.
  • FIG. 9 shows a Gummel plot comparison for the commercial HBT and QWBHBT.
  • FIG. 10 shows a plot of the current gain vs. collector current for the commercial HBT.
  • FIG. 11 shows a plot of current gain vs. collector current for the QWBHBT.
  • FIG. 12 shows I-V curves for the commercial HBT at a temperature of 150 0 K.
  • FIG. 13 shows I-V curves for the QWHBT at a temperature of 15O 0 K.
  • the techniques described herein relate to transistors, such as bipolar junction transistors (BJTs), having both a quantum well base and a quantum well emitter. Such a transistor can achieve high current gain, better breakdown voltage and higher operational frequency. In addition, tight quantizing control of electron flow can reduce the noise level in the device.
  • BJTs bipolar junction transistors
  • Prior attempts to manufacture quantum well base BJTs were focused on producing negative resistance devices.
  • the transistor structure described herein may be considered to be a double heteroj unction bipolar transistor (DHBT) with a quantum well base.
  • DHBT double heteroj unction bipolar transistor
  • the energy band profile of a DHBT can be used to create a quantum well for holes and a quantum barrier for electrons.
  • FIG. 1 An embodiment of a transistor 1 having a quantum well base and a quantum well emitter is shown in FIG. 1.
  • FIG. 2 shows an image of the transistor 1 after fabrication.
  • the base region 2 of the transistor 1 can be formed of a III- V semiconductor such as p-type doped GaAs having a doping concentration of 7*10 18 cm '3 .
  • the thickness of this base region 2 may be about 240 A, such that the thickness is comparable to the wavelength of the electrons passing through it.
  • the term "thickness" in this context refers to the effective base width which excludes the depletion region widths from the emitter-base junction and collector-base junction. This is only one example of a suitable thickness for the base region 2, as other thicknesses of the GaAs base region may be used that are the same as, substantially the same as, the wavelength of the electrons passing through this region.
  • the GaAs base region 2 can form a quantum well that confines the electrons in this region.
  • the combination of the lower energy gap p-type GaAs base region 2 sandwiched between two higher energy gap n-type InGaP regions 3, 4, can create a double heterojunction that results in the formation of a deep quantum well for the holes injected into the base from the base contact, and a quantum barrier for the electrons injected from the emitter through the base into the collector.
  • An n-type doped InGaP region 3 of the emitter, adjacent to the base region 2, is also shown in FIG. 1.
  • This InGaP region 3 of the emitter may have a thickness of 21 ⁇ A, or other suitable thickness, forming a quantum well with respect to the electrons passing between the emitter and the collector.
  • the base region 2 thus forms a first quantum well for the base, and the emitter InGaP region 3 forms a second quantum well for the emitter. These quantum wells may reduce the noise created by both electrons and holes.
  • the emitter may also have an n-type doped GaAs region 6 in contact with the InGaP region 3.
  • the GaAs region 6 may have a thickness of about 2000A or other suitable thickness.
  • the emitter may further include a highly n-type doped InGaAs region 7, which may have a thickness of about 650 A or other suitable thickness.
  • An emitter electrode 8 may be in contact with the InGaAs region 7.
  • a base electrode 9 may be in contact with the base region 2.
  • the InGaP region 4 of the collector may be 4O ⁇ A thick.
  • the collector has not been entirely formed of InGaP because it may be difficult to grow a sufficiently thick layer of InGaP in some circumstances.
  • the remaining sub collector and collector regions may be formed of a GaAs region 5 having a doping concentration of 2*10 16 cm '3 and 5*10 18 cm "3 , respectively.
  • other embodiments may use a collector layer entirely formed of InGaP formed using suitable manufacturing techniques.
  • a collector electrode 10 may be formed in contact with GaAs region 5.
  • the measurement is performed by increasing the collector voltage in small steps until the collector current shoots up quickly and the transistor fails catastrophically.
  • the corresponding collector voltage at the point of breakdown was recorded as the breakdown voltage.
  • a breakdown voltage of 19V was measured for the transistor, which indicates an improvement by almost 58% as compared to the breakdown voltage of 12V for a commercial HBT.
  • a heterostructure bipolar transistor was modeled where the base is designed as a quantum well.
  • the transistor structure includes a base layer of GaAs that is heavily p-type doped.
  • the 0.024 ⁇ m base is sandwiched between wide band gap In x Ga] -X P which forms the n-type emitter and collector layers immediately adjacent to the base.
  • the thickness of the base was chosen so that it is comparable to the wavelength of the electrons passing though it.
  • the remainder of the emitter and collector regions are formed of GaAs.
  • One goal of this design is to filter the energies and velocities of electrons as they pass through the base region that forms a quantum barrier to electrons and a quantum well to holes.
  • the thin quantum well improves the collection of injected carriers, which in turn boosts the DC gain ( ⁇ ) to 750 and increases the power of the transistor by a factor of six, in comparison to a commercially available HBT with a similar non-quantum well structure.
  • the gain of the device is increased by about 5 dB over the non-quantum base HBT.
  • the cutoff frequency is improved from 20 GHz to 50 GHz. Modeling of the transistor was done using Silvaco ATLAS software. The dimensional characteristics of a bipolar device's base are a major factor in determining its performance characteristics. Combining a thin base with various heterostructures allows the designer to leverage quantum effects to achieve favorable properties.
  • DHBT double heterojunction bipolar transistor
  • the concept is to use the existing energy band profile of a DHBT to create a quantum well with regards to the holes and a quantum barrier with regards to the electrons.
  • a quantum barrier in the base of an HBT, electrons from the emitter will travel through the base towards the collector with different velocities and energies.
  • the presence of the quantum barrier will restrict the allowable energy levels of the electrons passing through it resulting in a reduction of noise.
  • by maintaining sufficient spacing between the energy levels in the quantum barrier scattering due to optical phonons is minimized, further reducing noise.
  • the reduction in base width will also result in a large gain as is seen in NBHBTs.
  • This HBT has an emitter region formed of highly n-type doped cap layers of InGaAs at the emitter contact followed by a region of n-type GaAs and then a region of n-type InGaP.
  • the base includes 10 19 cm "3 p-type doped GaAs of a thickness of 1000 A .
  • the collector includes n-type GaAs.
  • QWBHBT quantum well base heteroj unction bipolar transistor
  • a quantum well was created in the base of the structure by creating a double heteroj uction.
  • the base material is still formed of 10 18 cm “3 p-type doped GaAs, but the thickness of this region is reduced to 240A so that it is comparable to the wavelength of the electrons passing through it.
  • An additional InGaP region in the collector adjacent to the base was added.
  • the thickness of both InGaP regions is 400 A and both regions are n-type doped.
  • the combination of the lower energy gap p-type GaAs region sandwiched between two higher energy gap n-type InGaP regions creates a double heterojunction that results in the formation of a deep quantum well for the holes injected into the base from the base contact and a quantum barrier for the electrons injected from the emitter through the base into the collector.
  • the remaining structure remains the same as in the commercial device.
  • the QWBHBT structure can be seen in Fig. 5.
  • the width of both modeled devices was 38.3 ⁇ m.
  • the phenomenon of losing control of the transistor operation is linked to the appearance in the base of a large number of free electrons that are screening out the depleted region of the collector junction.
  • the base area at this point behaves not as a regular doped semiconductor but rather as a semi-metal. Additionally, a region of negative resistance occurs at higher base currents and at lower collector voltages. At high output currents, a large number of electrons experience a change of mobility coming from the emitter material to the base material where mobility is lower.
  • AC gain in the form of the S 2 i parameter vs. frequency for a base current of 50 ⁇ A and a collector bias of 2.5V at an emitter bias of zero was also found.
  • Fig. 8 shows the S 21 in decibels plotted against frequency for both the QWBHBT and the commercial HBT. The plot shows that the QWBHBT device does not just possess a larger DC current gain but also an improvement of 5 dB of AC gain in the frequency range of 1-10 GHz. The simulation also predicts that the cutoff frequency of the QWBHBT is about 50GHz.
  • Figs. 10 and 11 show the change in the current gain with respect to the increase in the collector current for both of the transistors.
  • the commercial HBT shows a linearity of around 0.3 dB at collector currents of 20-4OmA with an average DC gain of 37.7 dB
  • the QWBHBT shows a linearity of around 0.4 dB at collector currents of 20-8OmA with an average DC gain of 57 dB.
  • Fig. 10 also shows how the gain starts decreasing as the output current increases for the QWBHBT.
  • Figs. 12 and 13 show the modeling results at a temperature of 150 K.
  • the commercial HBT results are unremarkable while the QWBHBT curves show distinctive plateaus indicative of quantization in the base of the device. Similar results have been observed and measured in other manufactured quantum devices. It should be noted that when the quantum simulator is not employed, that these plateaus are not present in the resulting I- V curves.
  • a QEBHBT transistor may be formed using materials such as GaAs and InGaP as described herein, other suitable materials may be used, as the techniques described herein are not limited to particular materials. For example, other types of III-V semiconductor materials may be used.

Landscapes

  • Bipolar Transistors (AREA)

Abstract

La présente invention concerne un transistor bipolaire à double hétérojonction (DHBT) ayant une base à puits quantique ainsi qu'un émetteur à puits quantique. Le profil de bande d'énergie d'un DHBT peut être utilisé afin de créer un puits quantique pour des trous et une barrière quantique pour des électrons.
PCT/US2010/001067 2009-04-10 2010-04-09 Transistor bipolaire doté d'une base à puits quantique et d'un émetteur à puits quantique Ceased WO2010117467A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US16843409P 2009-04-10 2009-04-10
US61/168,434 2009-04-10

Publications (2)

Publication Number Publication Date
WO2010117467A2 true WO2010117467A2 (fr) 2010-10-14
WO2010117467A3 WO2010117467A3 (fr) 2010-12-29

Family

ID=42936770

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2010/001067 Ceased WO2010117467A2 (fr) 2009-04-10 2010-04-09 Transistor bipolaire doté d'une base à puits quantique et d'un émetteur à puits quantique

Country Status (1)

Country Link
WO (1) WO2010117467A2 (fr)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000031800A1 (fr) * 1998-11-26 2000-06-02 Mitsubishi Denki Kabushiki Kaisha Dispositif a semiconducteur et son procede de fabrication
US7247892B2 (en) * 2000-04-24 2007-07-24 Taylor Geoff W Imaging array utilizing thyristor-based pixel elements
US7091082B2 (en) * 2003-08-22 2006-08-15 The Board Of Trustees Of The University Of Illinois Semiconductor method and device

Also Published As

Publication number Publication date
WO2010117467A3 (fr) 2010-12-29

Similar Documents

Publication Publication Date Title
TWI695504B (zh) 異質接面雙極性電晶體
CN109671770B (zh) 具有能隙渐变的电洞阻隔层的异质接面双极性晶体管结构
JP3935372B2 (ja) 改良型エミッタ−ベース接合を持つヘテロ接合バイポーラトランジスタ及びその製造方法
US6992337B2 (en) Gallium arsenide antimonide (GaAsSB)/indium phosphide (InP) heterojunction bipolar transistor (HBT) having reduced tunneling probability
US20040065898A1 (en) Heterojunction bipolar transistor having wide bandgap material in collector
US8957455B1 (en) Modulation doped super-lattice base for heterojunction bipolar transistors
JP5160071B2 (ja) ヘテロ接合バイポーラトランジスタ
US11049936B2 (en) High ruggedness heterojunction bipolar transistor structure
JP3853341B2 (ja) バイポーラトランジスタ
Kurishima et al. Performance of InP/InGaAs HBTs with a thin highly N-type doped layer in the emitter-base heterojunction vicinity
JP7403201B2 (ja) 化合物半導体ヘテロ接合バイポーラトランジスタ
WO2010117467A2 (fr) Transistor bipolaire doté d'une base à puits quantique et d'un émetteur à puits quantique
JP3629247B2 (ja) ダブルヘテロ接合バイポーラ・トランジスタ
Zhi et al. High-speed InGaAs/InP double heterostructure bipolar transistor with high breakdown voltage
JP2004200423A (ja) バイポーラトランジスタ
US20100200894A1 (en) Hetero junction bipolar transistor
US7297589B2 (en) Transistor device and method
Mil'shtein et al. Bipolar transistor with quantum well base
JPH06302623A (ja) トンネルトランジスタおよびその製造方法
US20250031395A1 (en) Heterojunction bipolar transistor and base-collector grade layer
JP2010287603A (ja) 化合物半導体素子及びその製造方法
JP3601305B2 (ja) 半導体装置
JP2001176881A (ja) ヘテロ接合バイポーラトランジスタ
Yang et al. InP double heterojunction bipolar transistors with chirped InGaAs/InP superlattice base-collector junction grown by CBE
ARAI et al. InP DHBT with 0.5 µ m Wide Emitter along< 010> Direction toward BM-HBT with Narrow Emitter

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10761999

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10761999

Country of ref document: EP

Kind code of ref document: A2