Nanofabrication and Devices (in ECE and ME Departments)

John Melngailis

Department of Electrical and Computer Engineering

&

Institute for Research in Engineering and Applied Physics.

University of Maryland, College Park

Nanofabrication

- electron beam lithography, (SEM with beam writing software, 20nm min. features) C.H. Yang

- focused ion beam, milling, induced deposition, etching, and implantation, 5-10 nm minimum beam

diameter, ~30nm features milled. K. Edinger, A. Stanishevsky, J. Orloff and J. Melngailis

- deep reactive ion beam etching, D. DeVoe

- aligner/bonder, R. Ghodssi

- new Engineering & Applied Sciences Bldg. (6000 sq. ft. class 1000, clean room), ready May,04

Engineering and Applied Sciences Building

Clean room

floor plan

6000sq. ft. Class 1000Space

Cross section view of clean room and subfab

 

FIB facilities

Nanofab 150 kV FIB system with alloy ion sources used for implantation of semiconductor devices

FEI-620 30 kV Dual-Beam SEM/FIB with Ga+ ion sourceMicrion FIB-2500 system with 50 kV Ga+

source and 5nm minimum beam diameter

FIB patterning of diamond films

Patterned CVD diamond microcrystal

A. Stanishevsky, Univ. of Maryland

Trenches focused-ion-beam milled in a diamond film.

30nm wide, 600nm deep

Focused Ion Beam Milled Cross Section of Part of an Integrated Circuit

Ion Beam Shaving Focused Ion Beam Milling

SNOM probeElectrochemical

probeScanning Gas-Nozzle “Nano-jet”

Electron Beam Induced Deposition Focused Ion Beam Implantation

Scanning Thermal Probe

AFM / MFM Probe Scanning Electric Field Probe

FIB/SEM fabricated Nano-Probes

Klaus EdingerLIBRA

Nanodevices-Electronic & optical

• quantum (C. H. Yang, et. al.) • modeling: nanoMOSFET’s, carbon nanotubes

(N. Goldsman & G. Pennington)• magnetic storage (R. Gomez, et al.)• FIB implanted JFET (A. DeMarco & J. Melngailis)• single photon tunneling (I. Smolyaninov & C. Davis)

C.H. Yanga, M.J. Yangb, Andy Chenga, Philip Changa, and J.C. Culbertsonb

Nanoelectronics Research

aDepartment of Electrical and Computer Engineering,University of Maryland, College Park, MarylandbNaval Research Laboratory, Washington DC

le

WL

l

Fabricated 30 nm conducting InAs wires by (I) MBE growth of heterojunctions, (II) electron beam lithography and (III) wet etching

Observed: 1D pure metal regime:

WW < le < l Ballistic regime:

LL < le < l

C.H. Yanga, M.J. Yangb, Andy Chenga, Philip Changa, and J.C. Culbertsonb

Nanoelectronics Research

aDepartment of Electrical and Computer Engineering,University of Maryland, College Park, MarylandbNaval Research Laboratory, Washington DC

Fabricated 100 nm diameter conducting InAs ring, and observed quantum interference due to wave-like electron transport.Left: AFM topographyBelow: Magnetoresistance

Numerical Boltzmann/Schrodinger Equations: CAD of Quantum Effects in Nanoscale Semiconductors

Neil Goldsman, ECE Dept. UMCP

Band Diagram Flow Chart

Quantum Domain Dispersion Relation of QM Well

..

Numerical Boltzmann/Schrodinger Equations: CAD of Quantum Effects in Nanoscale Semiconductors

Neil Goldsman, ECE Dept. UMCP Numerical

I-V Charactistics

Current Vector(SHBTE) Current Vector(QM-SHBTE)

..

Subthreshold Characteristics

Design and Theory of Carbon Nanotube Diodesby Gary Pennington and Neil Goldsman ECE Department University of Maryland

-V

•Results: Using the tube diameter dependence of the effective mass, band offset, dielectric constant, and hole concentration for an array of Y-junction multiwalled carbon nanotubes, we determined an theoretical analytical formula the junction current as a function of constituent tube diameters.

Array of Y-junction carbon nanotubes

Experiment: C. Papadopoulos et al., Phys. Rev. Lett 85, 3476 (2000).

R.D. Gomez, et al., Laboratory for Physical Sciences, College Park MD R.D. Gomez, et al., Laboratory for Physical Sciences, College Park MD and University of Maryland, College Park, MDand University of Maryland, College Park, MD

Mechanism: s-d exchange interaction

Demonstration of current-induced domain wall motion for novel magnetic device applications

L. Gan, S.H. Chung, K. Aschenbach, M.Dreyer and R.D. Gomez, IEEE Transactions on Magnetics 36, 3047, 2000.

Ballistic Nanocontact Magnetic Random Access Memory R.D. Gomez, Department of Electrical and Computer Engineering

Topography of interacting NiFe island arrays

Demonstration of Fabrication and Characterization of Single Domain Magnet

Arrays

H. Koo and R.D. Gomez, IEEE Transactions on Magnetics 37.

Ballistic Nanocontact Magnetic Random Access Memory R.D. Gomez, Department of Electrical and Computer Engineering

Schematic view of our experimental setup.

fiber

to PMT

prism

3BCMUgold film

pinhole

632 nm light

Single-Photon Tunneling

I.I. Smolyaninov, C.Davis et.al. ECE Dept.

Small smart systems &MEMS

• Don Devoe- mechanical resonators…• Reza Ghodssi- III-V MEMS, MEMS_VLSI integration• Elisabeth Smela- polymer mEMS

High-Q Piezoelectric Nanomechanical Filter Arrays

• Functional filter banks based on nano-scale piezoelectric NEMS structures:

– orders-of-magnitude size reduction compared to SAW devices– direct integration with VLSI (ZnO) and high-speed electronics (AlAs)– low power operation• Applications in miniature RF communications, spectrum analyzers, etc.

1

10

102

103

104

105

10-10 10-8 10-6 10-4 10-2 1

Volume (cm3)

Q

NEMS.Thin Film

Thin Crystal

Dielectric

PlanarDielectricLumped

Element

HTS

10+2

piezo

Piezoelectric resonator scaling

L=200nm

gap=20nmgap=L/10

Piezo (AlAs, ZnO)

Capacitive (poly-Si)

f=3GHz

L=30nm

beam length

f=60MHz

~ 34 m Deep Trench in Si SiO2

Bottom PtTop Pt

PZT

Input Signal

~ 34 m Deep Trench in Si SiO2

Bottom PtTop Pt

PZT

Input Signal Output Signal

Mechanical & thermal devices

• Hugh Bruck - funcionally graded materials• Klaus Edinger - scanning thermal nanoprobe

Functionally Graded Smart Thin Film

Mf >Troom

Ms <Troom

5 mm*>150.0°C

*<123.7°C

125.0

130.0

135.0

140.0

145.0

150.0 1 mm

Out-of-plane Displacement

Infrared Temperature Field

Nano Indenter XP

= 100 MPa

r

z

T

t

400 oC

Ms = 43 oC, Mf = 23 oC

Ms = 3 oC, Mf = -17 oC

U-DISPLACEMENT

100 nm 100 nmV-DISPLACEMENT

150 nm 150 nm

Before Actuation

After Actuation

Digital Image Correlation

Film-substrate interface

ATC 1200 SPUTTERING MACHINE “Micropump”

Functionally Graded Smart

Thin Film

“Microbubble”

Atomic Force Microscopy

Fabrication of Functionally Graded Thin Films

Nanoscale Structure and Deformation Characterization

Nanoscale Material Property and Stress Characterization

Microdevice Performance Characterization

Microscale Modeling of Device Performance

Force Modulation Microscopy

Dimension3000 SPM

1 m

T = 44 oCFinite Element

Analysis

Hugh BruckME Dept

Scanning Thermal ProbeKlaus Edinger

Me3 MeCp Pt precursor deposits a Pt/carbon mixture

Filament diameter ~ 30 nmTip end radius < 20 nm

Height: 2-5 m

LIBRA

Nanofabricated Scanning Thermal Probe Klaus Edinger, LIBRA

Topographic image (left): Only the metal leads are visible. The two buried resistors are indicated by the dotted line. Temperature image (right): The two buried resistors (heating current ~2mA) are visible.

• Free-standing 20-50 nm Pt “wire” grown by electron beam induced deposition from an organometallic precursor gas on an AFM type cantilever. • Low thermal mass; high sensitivity; high spatial resolution

•Passive mode: the resistance of the wire in contact with the sample is measured, using a low current temperature mapping

•Active mode: the wire is heated by applied an AC-current mapping of thermal conductivity and diffusivity.

LIBRA

Summary

• nanofabrication capabilities (e-beam/SEM, focused ion beam, MEMS, new EAS Building with clean room)

• nanodevices: electrical & optical

• nanoMEMS

• mechanical and thermal devices