IBM T.J. Watson Research Center

Jeehwan KimResearch Group

http://jeehwanlab.mit.edu

III-V epitaxy for low energy optoelectronics

Jeehwan KimMechanical Engineering

Materials Science and EngineeringResearch Laboratory of Electronics

Microsystem Technology Laboratories

Epitaxial strategies enabling low energy optoelectronics

Si photonic waveguide

antenna enhanced LED photodetector

Thrust 1: Optimization of LED stack• Continued efforts in provision of high p-doped InGaAs active region

Thrust 2: III-V hetero-integration on Si• Application of 2D material based layer transfer for exfoliation and hetero-

integration on Si

MIT growth capabilities

Thomas Swan/Aixtron close-coupled showerhead reactor

Hydride precursors for group IV and V

Unique group IV growth capability

1x6” or 6x2” wafer support

MOCVD reactor in substrate engineering lab at MIT

Target

High p-doping is necessary for improved bandwidth modulation

Challenges:• Obtaining C concentration in

target range > 4E19 cm-3

• Ensuring high dopant activation > 2E19 cm-3

• Maintaining In/Ga composition and growth rate

Growth challenges towards 100 GHz III-V antenna-enhanced nanoLED

Growth strategies:

• grow at low growth temperature, V/III ratio• post growth anneal in N2 to activate dopants (removal of H)• use XRD data to feed back into precursor flow rates for next run

Dopant activation with high temp anneal

qx (nm-1)

qz (n

m-1

)

4.815 4.82 4.825 4.83 4.8356.74

6.76

6.78

6.8

6.82

6.84

6.86

6.88

InP substrate

InGaAs

fully strained

XRD compositional analysis to confirm lattice matched InGaAs

Laser power = 500uWWavelength = 1000nm20X objective

without anneal

with anneal 𝜏𝜏 ≈ 140ps

𝜏𝜏 ≈ 700ps

Time-resolved (UC Berkeley)

High C doping with right In/Ga contents

Proposed structures

SI-InP (substrate)

p-InP (250 nm, 1E18 Zn)

p-InGaAs (70nm, 2e19 C)

n-InP (30 nm, 5E18 Si)

n-InGaAs (20nm, 2E18 Si)

InP cladding (100 nm, UID)

InP (20nm, UID)

InP setback (20 nm, UID)

p-InGaAsP contact (150nm, 5e18 Zn)

SI-InP (substrate)

p-InP (250 nm, 1E18 Zn)

p-InGaAs (70 nm, 2E19 C)

n-InP (30 nm, 5E18 Si)

n-InGaAs (20 nm, 2E18 Si)

InP cladding (100 nm, UID)

InP (20 nm, UID)

InP setback (20 nm, UID)

SI-InP (substrate)

InP (100 nm, UID)

p-InGaAs (70 nm, 2E19 C)

InP (30 nm, UID)

InGaAs (20 nm, UID)

InP (20 nm, UID)

Continued optimization of antenna-enhanced LED structure

Strategy to interointegrate nano-LED on Si: Remote epitaxy

Graphene

GaAsSubstrate

Penetrated covalent field

Van der WaalsField >

???

400 nm

400nm

(100) GaAs Wafer

(100) GaAs Film

(100) GaAs Wafer

Polycrystalline

EBSD map HRTEM

AFM

RMS =0.3 nm

Perfect single-crystalline planar films can be grown on 2D materials

Application: 2D material-based layer transfer (2DLT)

Y. Kim et al., and J. Kim., Nature 544, 340 (2017)

Monolayer graphene + Wafer

= Copy Machine (Film producer)

GaAsfilm

GaAsSubstrate

Remote epitaxy works for any compound materials

GaAs (100) InP (100) GaP (100) GaAs (111) GaN (1000)

W. Kong,…and J. Kim*, Nature Materials (2018)

Polarity governs remote atomic interaction through 2D materialsDFT thermodynamic calculation

Kinetic Monte Carlo simulation

Polarity of 3D materials determines field penetration

Polarity of 2D materials determines field screening

W. Kong,…and J. Kim*, Nature Materials (2018)

Remote heteroepitaxy can reduce dislocation density

Fully strained InGaP on GaAs

exx eyy

Relaxed InGaPon graphene

ex

x

ey

y

ConventionalEpitaxy

Remote epitaxyon graphene

1% strained InGaP on GaAs

Spontaneous relaxation occurs on graphenewithout involvement of dislocation!

4% strainedInP on GaAs

Conventional epitaxy Remote epitaxy

Strained Fully relaxed

2DLT for advanced heterointegration

III-V optoelectronics on Si

InGaAs

InP wafer

Remote epitaxy of InGaAsthrough graphene

InP wafer

InGaAsP bottom contactInP bottom contact

InP claddingInGaAs activeInP cladding

InP top contact

InGaAs top contact

Remote epi of InGaAs LED

InP wafer

Peel

Si photonic waveguide

Antenna enhanced LED (TRANSFERRED) photodetector

Collaborators: Eugene FitzegraldMing Wu

Nanoelectronics Group at MIT

9 Ph.D. students Yunjo Kim, Kuan Qiao, Scott Tan, Seungchan Ryu, Chanyeol Choi, Subin Bang, Kuangye Lu, JatinPatil, Skye Ngo

10 Postdocs Shinhyun Choi, Wei Kong, Sanghoon Bae, Hanwool Yeun, Hyun Kum, Peng Lin, Yeongin Kim, Jaewoo Shim, Sungkyu Kim, Lingping Kong

10 Interns J. Fishman, G. Theopan, Y. Lee, D.Lee, B. Lee, L.

Sponsors

Heterointegration Group

Wafer-scale 2D Materials GroupRemote Epitaxy Group

Neuromorphic Computing Group

GaAs (100)InP (100) GaP (100)GaAs (111)GaN (1000)

0 100 200 300 400 500 600 7000

1

2

3

4

5

0 1 2 3 4

10-11

10-8

10-5

Voltage (V)

Cur

rent

(A)

0 1 2 3 4

Voltage (V)

Nature (2017), Nature Materials (2018)

Nature Materials (2018)

Science (2018)