藉由臭氧水氧化製程研製具有金屬-氧化物-半導體閘極結構之砷化鋁鎵/砷化銦鎵擬晶式高電子遷移率電晶體

-

-/

Investigations on AlGaAs/InGaAs pHEMTs With

Metal-Oxide-Semiconductor Gate Structure by Using

Ozone Water Oxidation Technique

學號：D9728953、D9736188、D9886381、D9736229

/ -- - / -- -- / / 1.2 × 100 m2 (IDSS0) 208 151 mA/mm (gm, max) 162 129 mS/mm (Vpinch-off) –1.05 –1.23 V (fT) 14.64 10.40 GHz (fmax) 27.09 14.64 GHz (NFmin) 1.03 1.51 dB (P.A.E.) 42.4 32.9% / -

-Abstract

AlGaAs/InGaAs high electron mobility transistors (HEMTs) using ozone water treatment with metal-oxide-semiconductor gate structure is successfully made in our studied. As a surface passivation layer and metal-oxide-semiconductor HEMTs (MOS-HEMTs) using ozone water as gate oxide has been investigated. We compared with the conventional HEMTs and MOS-HEMTs, the MOS-HEMTs improve the surface characteristics and decrease the gate leakage. Hence, upgrade the devices DC characteristics.

Firstly, we simply state a number of related fundamentally knowledge in chapter 1. We also introduce the structure layer design and two-dimensional electron gas in chapter 2, and then we report the process for fabricating device including wafer orienting, source and drain metallization, mesa isolation, and gate metallization in detail in chapter 3. In chapter 4, first we report the Hall measurement and performance, and then we discuss the detail characteristics of our devices AlGaAs/InGaAs pHEMT with MOS-HEMT and a Conventional Au gate. In the first places are DC characteristics at 300 K such as the saturation drain current density, the maximum extrinsic transconductance, the pinch-off voltage. In the second places show the RF characteristics such as the unity current gain cut-off frequency, the

maximum oscillation frequency, the high frequency noise, and the

power-added –efficiency. Finally, we have a conclusion for this thesis in chapter 5. In our case study, we research AlGaAs/InGaAs high electron mobility transistors, which manufacture difference gate structure. One is metal-oxide-semiconductor AlGaAs/InGaAs high electron mobility transistors, the other is conventional AlGaAs/InGaAs high electron mobility transistors. In the room temperature, our gate dimension is 1.2 × 100 m2. The sample of metal-oxide-semiconductor and

respectively as follow: the saturation drain current density( IDSS0) of (208

151 )mA/mm, the maximum extrinsic transconductance (gm,max) of (162 129)

mS/mm, the pinch-off voltage (Vpinch-off) of (–1.05 –1.23) V, the unity current gain

cut-off frequency(fT) of (14.64 10.40) GHz, the maximum oscillation frequency (fmax)

of (27.09 14.64) GHz, the high frequency noise (Nfmin) of (1.03 1.51) dB, and the

power-added-efficiency (P.A.E.) of (42.4 32.9 %).

From our experimental results shows AlGaAs/InGaAs high electron mobility transistors with using ozone water to form the metal-oxide-semiconductor gate structure can obtain lower output conductance, higher gain and higher breakdown voltage. Then, we can improve DC characteristics and microwave characteristics. Hence, our device is suitable for using in the high-gain and high-power MMIC devices.

1

1

2

pHEMT

3

2-1 pHEMT

3

2-2 pHEMT

4

2-3

8

3

1鎵

3-1

1鎵

3-2

13

3-2-1

14

3-2-2

14

3-2-3

15

3-2-4

16

3-2-5

16

4

18

4-1

18

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19

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26

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1111

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5

[12-15]

2 3

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Au 3鎵鎵

2222

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2-2 pHEMT

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1

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1鎵18 cm-3 HEMT HEMT gm 銦fT) [16]

2

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HEMT 、 2鎵Å 5鎵 Å

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2- DEG HEMT 2-1 2-2 2-3

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Fazal Ali

Fazal Ali

Fazal Ali

Fazal Ali

Aditya Gupta

Aditya Gupta

Aditya Gupta

Aditya Gupta

HEMTs and HBTs

HEMTs and HBTs

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2-

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2DEG 2-5-a InGaAs

GaAs 4 5 InGaAs

2

22

2-

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-4

44

4

銦a)AlGaAs/GaAs

銦a)AlGaAs/GaAs

銦a)AlGaAs/GaAs

銦a)AlGaAs/GaAs

銦b)2DEG

銦b)2DEG

銦b)2DEG

銦b)2DEG

2

22

2-

--

-5

55

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3333

3-1

Au 3-1 MOS HEMT 3-2

MOS -HEMT Au HEMT 3-1 Au HEMT

MOCVD 100 : (1) 5000Å (2) 1000Å Al0.22Ga0.78As (3) δ 1.2× 1012 cm-2 (4) 75Å Al0.22Ga0.78As (5) 120Å In0.24Ga0.76As (6) 75Å Al0.22Ga0.78As (7) δ 4.5× 1012cm-2 (8) 500Å n-Al0.22Ga0.78As 5× 1017cm -3 (9) 150Å n - 5× 1018cm-3

: 1.2

: 1.2

: 1.2

: 1.2 ×

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1鎵鎵

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3

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--

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2

2

2

BB

B

B

3-2

3-3 (1) (2) (3) (4) Channel Buffer Substrate Schottky Cap Channel Buffer Substrate Schottky Cap

1

11

1

2

22

2

33

3-

3

--

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33

3

3-2-1

lift off (100) (011)

3-2-2

FH -64鎵鎵L 銦H3PO4 H2O2 H2O=1 1 3鎵) Channel Buffer Substrate Schottky Cap Channel Buffer Substrate Schottky

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銦Au/Ge/Ni)

Au/Ge/Ni)

Au/Ge/Ni)

Au/Ge/Ni)

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Au

Au

Au

1. 2. 3. 4. 5. 6. 7. 8. 9.

3-2-3

NH4OH H2O=1:1 FH -64鎵鎵L 9鎵 1鎵 20 Au/Ge/Ni 84:12:4 6 ×1鎵-6 7 ×1鎵-6 torr Au lift-off Au : 1. 2. 3. 4. 5. 6. 7.

9. 1鎵.

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NH4OH H2O=1:1

銦H3PO4 H2O2 H2O=1 1 30)

Au lift off HEMT

1. 2. 3. 4. 5. 6. 7. 8.

3-2-5

/ / /

lift off 1.2 × 1鎵鎵 m2 - 7 m pHEMTs H2O2 Welsbach T-816 17.7 p.p.m. pHEMT 1nm /min 1鎵

4444

/ pHEMT MOS- HEMT

， A / pHEMT B MOS - HEMT

4

44

4-

--

-1

1

1

1

5000G 300K ns 2.85×1012cm-2 µn 5030 cm2 V-S -1 10 2.96×1012cm-2 5060cm2(V-s)-1 4- 1 10 ， ns ， 2DEG [24-25] Sheet Resistivity (ohm/sq) Mobility (cm2/V-s) Sheet concentration (cm-2) µn× ns (1/V-s) Conventional 453 5030 2.85×1012 1.43×1016 With Ozone water treatment 10 minutes 416.8 5060 2.96×1012 1.77×1016 4444----1111

4

44

4-

--

-2

22

2

(Agilent 35670A) (BTA 9812B) 1Hz 100 KHz VDS = 2.5 V Ids= 100 mA/mm IDS 4-1 V_D = 2.5 V , V_G = 0 V Sample A V_D = 2.5 V , V_G = -0.5 V 1 10 100 1000 10000 100000 1E-21 1E-20 1E-19 1E-18 1E-17 1E-16 1E-15 1E-14 1E-13 1E-12 Sample B A v e ra g e I n p u t-N o is e V o lt a g e S p ec tr a , S IV ( V 2 /H z ) Frequency (Hz) 4 44 4----1111 AlGaAs/InGaAs pHEMTs AlGaAs/InGaAs pHEMTs AlGaAs/InGaAs pHEMTs AlGaAs/InGaAs pHEMTs

4

44

4-

--

-3

33

3

300K

1.2 × 100 µm2 - 7µm KEITHLEY4200

4

44

4-

--

-3

33

3-

--

-1

1

1

1

-

--

-

4-2, 4-3 A B VGS(max) 1 V - 2 V IDS VDS -0.5V/step 4-4 A B A B B / [25-26] 0 2 4 0 100 200 300 400 D r a in C u r re n t D e n si ty ( m A /m m ) Drain-Source Voltage (V) 0 2 4 0 100 200 300 400 V_GS = 1 V~ -2 V, step = -0.5 V Sample A 4444----2222 A AA A 3鎵鎵K3鎵鎵K3鎵鎵K3鎵鎵K

0 2 4 0 100 200 300 400 V_GS = 1 V~ -2 V, step = -0.5 V D r a in C u rr e n t D e n si ty ( m A /m m ) Drain-Source Voltage (V) Sample B 4444----3333 BBBB 3鎵鎵K3鎵鎵K3鎵鎵K3鎵鎵K 0 2 4 0 100 200 300 400 V_GS= 1 V~ -2 V step= -0.5 V D r a in C u r r en t D e n si ty ( m A /m m ) Drain-Source Voltage (V) Sample B 0 2 4 0 100 200 300 400 Sample A 4444----4444 AlGaAs/InGaAs pHEMTs

AlGaAs/InGaAs pHEMTsAlGaAs/InGaAs pHEMTs

4

44

4-

--

-3

33

3-

--

-2

2

2

2

(gm) IDS - VGS VDS=2.5 V A B 4-5 4-6 0 50 100 150 200 E x tr in si c T ra n sc o n d u ct a n ce ( m S /m m ) -2 0 20 100 200 300 400 D ra in C u rr en t D en si ty ( m A /m m ) Gate-Source Voltage (V) V_DS = 2.5 V Sample A 4 44 4----5555 A AA A 3鎵鎵K3鎵鎵K3鎵鎵K3鎵鎵K Sample B V_DS=2.5 V 0 50 100 150 200 E x tr in si c T ra n sc o n d u ct a n ce ( m S /m m ) -2 0 20 100 200 300 400 D ra in C u rr en t D en si ty ( m A /m m ) Gate-Source Voltage (V) 4 44 4----6666 B BB B 3鎵鎵K3鎵鎵K3鎵鎵K3鎵鎵K

4-7 A B gm IDS Sample B 0 50 100 150 200 E x tr in si c T ra n sc o n d u ct a n ce ( m S /m m ) -2 0 2 0 100 200 300 400 D ra in C u rr en t D en si ty ( m A /m m ) Gate-Source Voltage (V) V_DS=2.5 V Sample A 4 44 4----7777 AlGaAs/InGaAs pHEMTs

AlGaAs/InGaAs pHEMTsAlGaAs/InGaAs pHEMTs

AlGaAs/InGaAs pHEMTs 3鎵鎵K3鎵鎵K3鎵鎵K3鎵鎵K Sample A Sample B Idss0 (mA/mm) 151 208 Id,max (mA/mm) 292 374 gm,max (mS/mm) 129 162 GVS (V) 0.932 1.105 Vth (V) -1.23 -1.05 4 44 4----2 2 2 2 gmgmgmgm IIIIDSDSDSDS VVVVthththth GVSGVS GVSGVS 4-2 IDSS ID(max)

MOS HEMT MOS- HEMT

， IDSS0 ID(max) gm(max) GVS [27]

ε

φ

( ) 2DEG d d n q c E q B th V ∆ + − ∆ − = 銦4-1) ΦB ∆Ec InxGa1- XAS d + ∆d 2DEG 4-1 MOS – HEMT 2DEG 2-DEG

4

44

4-

--

-3

33

3-

--

-3

3

3

3

4-8 HEMT MOS - HEMT BVGD

Von IG/ W 1mA/mm -40 -30 -20 -10 0 -1.0 -0.5 0.0 0.5 1.0 Sample A Sample B G a te C u r r en t D en si ty ( m A /m m ) Gate-Drain Voltage (V) 0.0 0.5 1.0 1.5 2.0 0.0 0.5 1.0 G a te C u rr en t D e n si ty ( m A /m m ) Gate-Drain Voltage (V) 4 44 4----8888

Sample A

Sample ASample A

Sample A SampleSample SampleSample BBBB

BV BVBV BVGDGDGDGD銦V)銦V) 銦V)銦V) 13 29.5 4444----3 3 3 3 4-3 B A

4

44

4-

--

-3

33

3-

--

-4

4

4

4

4-9 A B : d m o m V g g r g A = ⋅ = (4-2) VDS = 2.5 v 4-4 4-4 B A B

0 1 2 3 4 0 40 80 120 160 200 V GS = 0 V E x tr in si c T ra n sc o n d u ct a n ce ( m S /m m ) a n d O u tp u t C o n d u c ta n c e (m S /m m ) Drain-Source Voltage (V) Sample A V GS = -0.5 V V o lt a g e G a in (V /V ) g_m g_d AV 0 50 100 150 200 250 Sample B 4 44 4----9999 AlGaAs/InGaAs pHEMTs

AlGaAs/InGaAs pHEMTsAlGaAs/InGaAs pHEMTs

AlGaAs/InGaAs pHEMTs 3鎵鎵K3鎵鎵K3鎵鎵K3鎵鎵K Sample A Sample B gm (mS/mm) 129 162 gd (mS/mm) 1.08 0.92 Av(V/V) 106 145 4 44 4----4 4 4 4 VVVVDSDSDSDS=2.5V=2.5V=2.5V=2.5V gmgmgmgm gdgdgdgd Av Av Av Av

4

44

4-

--

-4

44

4

HP 8510B 0.2 50 GHz cascade 1.2 × 100 µm2 7 µm HP Eesof Touchstone S 0dB H21 fT

)

(

2

GS GD m T

C

C

g

f

+

≈

π

銦4-3) and 2 1 0 max

]

2

)

(

[

2

_{G S GD} T

C

R

R

G

f

f

π

+

+

≈

銦4-4) Sample A Sample B fT (GHz) 10.40 14.64 fmax (GHz) 14.64 27.09 4-5 1.2 ×××× 100 m2 fT fmax 4-10 4-11 A B (fT) (fmax) fT fmax VDS= 2.5 v 4-5 B A fT 40.1% fmax 85.04% 1 10 0 10 20 30 40 f_T = 10.40 GHz f_max = 14.64 GHz G a in ( d B ) Frequency (GHz) Sample A V_DS = 2.5 V, V_GS = -0.5 V 4 44 4----1鎵1鎵1鎵1鎵 A A A A 1.21.2 1.21.2 ×××× 1111鎵鎵鎵鎵鎵鎵 鎵鎵 mmmm2222

1 10 0 10 20 30 40 G a in ( d B ) Frequency (GHz) Sample B V_DS = 2.5 V, V_GS = 0 V f_T = 14.64 GHz f_max = 27.09 GHz 4 44 4----11111111 B BB B 1.21.21.21.2 ×××× 1111鎵鎵鎵鎵鎵鎵鎵鎵 mmmm2222

4

44

4-

--

-5

55

5

AB :

=

−

×

100

%

DC in out dd a

P

P

P

η

銦4-5) Sample A Sample B P.A.E. (%) 32.9 42.4 Pout(dBm) 12.3 13.7 Gs (dB) 11.5 12.64

2.4GHz 4-12 4-13 (PAE) 1.2×100 µm2 VDS = 2.5 V A B (PAE) (Pout) (Gs) 4-6 4-6 B (P.A.E.) (Pout) (Gs) -20 -15 -10 -5 0 5 10 0 5 10 15 20 O u tp u t P o w e r (d B ) & P o w e r G a in ( d B m ) Input Power (dBm) Sample A V_DS = 2.5 V, VGS = -0.5 V G_{S P} out P. A. E. 0 10 20 30 40 P o w er A d d e d E ff c ie n c y ( % ) 4 44 4----12121212 A A A A 2.4GHz2.4GHz2.4GHz2.4GHz -20 -15 -10 -5 0 5 10 0 5 10 15 20 O u tp u t P o w er ( d B ) & P o w er G a in ( d B m ) Input Power (dBm) V_DS=2.5 V, V_GS= 0 V P_out 0 10 20 30 40 P o w er A d d ed E ff ci e n c y ( % ) Sample B G_S P. A. E. 4 44 4----13131313 B B B B 2.4GHz2.4GHz2.4GHz2.4GHz

4

44

4-

--

-6

66

6

4-14 4-15 (NFmin) 1.2 × 100 µm2 1 8GHz HP8970B 1 2 3 4 5 6 0 1 2 3 4 M in im u m N o is e F ig u re ( d B ) Frequency (GHz) V DS = 2.5 V ,VGS = -0.5 V Sample A 0 5 10 15 20 25 A ss o ci a te d G a in ( d B ) 4 44 4----14141414 A AA A 1 2 3 4 5 6 0 1 2 3 4 V_DS= 2.5 V ,V_GS = 0 M in im u m N o is e F ig u re ( d B ) Frequency (GHz) Sample B 0 5 10 15 20 25 A ss o c ia te d G a in ( d B ) 4 44 4----15151515 B BB B

Sample A Sample B NFmin (dB) 1.51 1.03 Associated gain (dB) 2.13 2.43 4444----7777 2.4GHz2.4GHz2.4GHz2.4GHz : m g s gs g R R fKC NF_min ≈1+2

π

+ 銦4-6) 4-7 (NFmin) (4-6) B B (NFmin) A

5555

/ MOS-HEMTs MOS-HEMTs HEMTs HEMT / MOS-HEMTs 162 mS/mm ( 126%) 208 mA/mm ( 138%) 13.7 dBm ( 114%) 12.64 dB ( 110%) 42.4% ( 129%) -29.5 V ( 227%) 14.64 GHz ( 141%) 27.09 GHz ( 185%) / MOS-HEMTs

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