Nanopackaging - Portland State University

1 downloads 0 Views 3MB Size Report
Apr 21, 2009 - 20nm-sized Ag particles annealed at different temperatures for 30 minutes: (a) room .... (b) CNTs treated H2SO4/HNO3 16hrs 50oC. 4/21/2009 ...
Nanopackaging: Nanotechnologies & Electronics Packaging Part D ECAs, Simulation, & Nanoelectronics Packaging James E. Morris Department p of Electrical & Computer p Engineering, g g, Portland State University, Portland, Oregon, USA [email protected]

Nanotechnologies in ECAs † †

ECA/ICA/ACA/ACP/ACF/NCA !!!! ICAs „ „ „

† † † 4/21/2009

Nanoparticles Sintering Surface treatments

ACAs, NCAs, & miscellaneous CNTs Microvias 2

1

Nanoparticles

Percolation limits of different ICA filler particles 4/21/2009

3

Ag nanoparticles added to Ag-ICA [Fan/Su/Qu/Wong ECTC’04] 4/21/2009

4

2

Ag nanoparticles added Fan/Su/Qu/Wong [ECTC 2004] †

†

† 4/21/2009

80% Ag + nanoparticles: ti l no effect 70% Ag + nanoparticles: percolation threshold Ag more effective as flakes 5

ICA: Mach, Richter, & Pietrikova Proc. ISSE 2008 Paper D003 pp. 230-235 Addition of Ag nanoparticles Specimen

Nanoparticles Dimensions (nm)

Concentration % (wt.)

Processing

S1

(3 - 55)

10

S2

(3 - 55)

20

Ag flakes substituted with Nanoparticles

S3

(3 - 55)

30

S4

(80 – 100)

3.8

S5

(6 – 8)

3.8

S6

(80 – 100)

7.4

S7

(6 – 8)

7.4

S01

Bis-phenol epoxy resin; 75 wt% Ag flakes 6-8µm

4/21/2009

Nanoparticles added

I‐V Non‐linearity

6

3

Nanoparticle inclusion in epoxy: AgNO3

Micro‐particles

[Wong et al, ECTC’06]

(hardener)

Nano‐particles 4/21/2009

7

Nanoparticle Sintering [Wong et al, ECTC’06]

4/21/2009

8

4

Isotropic Conductive Adhesives (ICAs) 20nm-sized Ag particles annealed at different temperatures for 30 minutes: (a) room temperature (no annealing); (b) annealed at 100oC; (c) annealed at 150oC; (d) annealed at 200oC and (e)annealed at 250oC. Lu et al (Markers: (a) 3μm (b) 2μm (c) 2μm (d) 3μm (e) 3μm ) (a)

(b)

((d))

(c)

(e) Liu et al

4/21/2009

9

A

Das & Egitto

(a) A' A

(b) A' Use of blind vias increases wiring density.

ICA Microvia Fill (PWB)

75°C micro/nano Ag  sintering

LMP

Cu

Ag 4/21/2009

10

5

Nano-particle sintering [Wong et al, ECTC ’04 & ’06]

Surfactants: 5% diacids

Without surfactant

↓ With surfactant ↓ 4/21/2009

11

Stearic acid can be removed/replaced by short-chain dicarboxylic acids, with strong affinity for Ag surface (e.g. malonic acid) Li/Moon/Li/Wong ECTC 2004] resistivity((Ohm-cm)

1.60E-03 1.40E-03 1.20E-03 1.00E-03 8.00E-04 8.00E 04 6.00E-04 4.00E-04 2.00E-04 0.00E+00 ICA

ICA w ith Acid M

ICA w ith Acid A

ICA w ith Acid T

t le ad

malonic oxalic

0.06

terephtha

0.04

epoxy

0.02 0

r

C urr en

adipic

0.08

ete

stearic

0.1

ltim vo

clean

0.12

To

contact resistance(ohm)

0.16 0.14

4/21/2009 1

10 contact force(gram )

100

Experimental resistances with short‐ chain acids

12

[Qu – APM’05]

6

Anisotropic Conductive Adhesive (ACA) Enhancement (Rongwei Zhang et al ECTC’08)

Resistance ~mΩ █ █ █ █ SAM‐1:

4/21/2009

“Molecular wires” Oxide reduction Lower resistance Higher max current

13

10-20 nm nano-Ag fillers for NCAs (AgNO3 added to polymer)

4/21/2009

[Li/Moon/Wong ECTC’06]

14

7

CNT-PP (petroleum pitch) composite (C mesophase) fill for fillers f conductive pastes [Bondar et al, ECTC’05] 4/21/2009

15

Ag nanowire ACF (Au seed, Co alignment) [Lin et al, ECTC’05]

4/21/2009

16

8

Addition of CNTs to NCAs: 0.03 wt% CNTs increases electrical and thermal conductivities c. 20%

DSC

Jiang, Min, Moon, & Wong, Proc. ECTC 2008 pp. 1385-1389 4/21/2009

17

Zhang, Jiang, Liu, & Inoue ICEPT/HDP 2008 E3-04 Effects of CNT & Ag powder addition Sample

AF2 epoxy % matrix

3-10µm % Ag flakes

0.5-1µm % Ag powder

Vol % CNT

Resistivity µΩ.cm

AgF201

60.762

38.238

1

0

45

AgF202

60.762

37.238

2

0

39

AgF203

60.762

36.238

3

0

40

AgF204

60.762

35.238

4

0

39

AgF205

60.762

34.238

5

0

48

AgF206

60.762

39.238

0

0

52

3F201

60.762

38.138

1

0.1

34

3F202

60.762

37.938

1

0.3

36

3F203

60.762

37.738

1

0.5

29

CNT dispersion in epoxy: (a) CNTs untreated

4/21/2009

(b) CNTs treated H2SO4/HNO3 16hrs 50oC

18

9

Interface effects on the conductivity of CNT composites [Yan et al, Nanotechnology 2007]

4/21/2009

19

Microsprings (Ma et al) Sputter deposition: Ti release layer

Ti Release layer Sputter deposition: Mo80-Cr20 (Stress-engineering) Mo80-Cr20 metal

Pattern interconnect by photolithography

Define release window

Substrate

Photoresist

Etch release layer

Interconnect curls up automatically

4/21/2009

20

10

Nanosprings (Ma et al)

(a) Bare wafer

(b) Release layer deposition Single Layer

Bi-Layer

(c) Spin resist layer(s)

100 90 80 70 60 50 40 30 20 10

800 700 600 500 400 300 200

Width (nm)

((f)) Ultra-sonic removal of resist leavingg patterned p metal

900

(e) Metal deposition with intrinsic stress gradient

1000

(a)

(d) Pattern resist

(g) Spin resist and pattern for release

(h) Selectively etch release layer; intrinsic stress gradient causes cantilever to curl up

4/21/2009

21

Molecular Dynamics (* van der Sluis et al) Tinitial

Loading Conditions + repulsive potential ∝ 1 / r m

potential energy

Initial Conditions

total potential

r

Particles r0 attractive energy ∝ 1 / r n

-

Boundary Conditions 4/21/2009

Potential functions 22

11

Molecular Dynamics (* Fan & Yuen) Modeling of interface H2O diffusion, CNTs, etc

Adhesion increases with Cu2O growth, decreases with void development

EMC →

Cu2O → 23

MD simulation snapshots of the Cu2O/EMC system, showing void development at the interface

Nanoscale Modeling

(van der Sluis et al)

Molecular Dynamics; interscale interfaces Time WLCSP

Years dsDNA

Hours

Finite Element Method (Static)

Minutes SiOC:H

Seconds

Mesoscale Modeling (Segments)

Microseconds Atom

Molecular Dynamics (Atoms)

Nanoseconds Picoseconds Femtoseconds

Quantum Mechanics (Electrons)

e.g. Drug delivary Cell

e.g. Crystallisation, Transistor

e.g. Catalyst, electronics

Distance 4/21/2009



1nm

1μm

1mm

meters

24

Need software “interface” packages to transport modeling results between length scales

12

Nanoelectronics Packaging † † † †

nm CMOS Single electron transistor (SET) Discussion: CNTs, molecular, RTDs, spintronics, etc Sensors

4/21/2009

25

Nano-CMOS Packaging (Mallik)

4/21/2009

26

13

Nano-CMOS Packaging (Mallik)

4/21/2009

27

Nano-CMOS Packaging (Mallik)

M1 M2

Via’s

M3

Low K ILD M4

Interconnects Etch stop

M5

Low k ILD Porous dielectrics Brittle material Stress increasing problem Compliant interconnect

CNTs on solder bumps

4/21/2009

28

14

Single electron transistor (SET) as example Metal nanodot as simple SET example (a) Gate Capactor

Quantum dot (Island)

Source

Drain

Tunneling Junctions

(b)

d

Rd , Cd Qd

Vd C g , Qg

V ds

Island Qnet

g Vg

Vgs

Rs , Cs Qs

Vs

Radehaus et al s

4/21/2009

29

Coulomb block & SET: Electric field & temperature

T=0°K: abrupt threshold at V=δE/q  4/21/2009

T>0°K: randomly charged exp‐δE/kT

30

15

Nanoparticle Charging: the Coulomb Block (Morris) Spherical nanoparticles, radius r, separation s Electrostatic charging energy:

ΔE =

q2 q2 ⎡ 1 1 ⎤ → − 4πεr 4πε ⎢⎣ r r + s ⎥⎦ r 0

Electrostatic charging energy



Field  assistance

r+s

x

E(x) -q q Fx

Net thermal barrier →0 for qV=∆E 0.5nm

1nm

4/21/2009

2nm

4nm

31

Electrostatic activation/charging energy (usually stated δE=q2/4πεr)

δE = (q 2 / 4π ε )(r −1 − (r + s ) −1 ) − (2r + s ) q F

when F < (q / 4π ε )(r + s ) −2 and at high fields 1

δE = (q 2 / 4π ε )r −1 + (r / s)(2r + s)q F − (q 2 / 4π ε s) 2 ((2r + s)q F )

until 4/21/2009

δ E →0

when

q V = (1 + s / r ) δ EV =0

1

2

32

16

The geometry of 2 ellipsoidal nanodots of eccentricity e = (1-(t/r)2)½

4/21/2009

33

δE for oblate spheroids with applied field δE = q2/C = (q2/4πεR)(2/e)[sin-1e-sin-1(e(1-p)/(1+p))]/(1-p)-qREa for Ea