BASELINE CMOS 170 PROCESS FLOW

Seq. Step No.

PROCESS STEP

SUB STEPS

TOOL / RECIPE

TARGET AND PROCESS SPEC

Notes

Date completed/ Operator

Process control

1

STARTING WAFERS

36 - 63 ohm-cm, p-type, <100>, 6"

10 wafers + 2 monitors (PCH, NCH)

9/6/2005 Horvath

2

INITIAL OXIDATION

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

Include 2 dummies for PM etch characterization

9/6/2005 Horvath

Processed in Tystar1, TCA

b) Std. clean wafers

Sink 6

Piranha + 25/1 HF until dewet

9/6/2005 Horvath

c) Dry oxidation

Tystar2, 2DRYOXA

Target = 250A       950C, 30 min; 20 min N2 annealing

Measure oxide thickness

9/6/2005 Horvath

Tystar1, 1GATEOXA Oxide thickn: Top  Cen (Nanospec)     190A 200A

3

ZERO LAYER PHOTO

ASML

Std. litho                Mask: COMBI

Defines ASML alignment PM marks

9/7/2005 Horvath

Hard bake in oven

4

SCRIBE WAFERS

Diamond pen

Scribe numbers into the photoresist

Numbers will be etched into Si during the following etch

9/7/2005 Horvath

5

ZERO LAYER ETCH

a) Etch through oxide

Centura MxP+       recipe: MXP_OXSP_ETCH

250A oxide etch, monitor endpoint

9/7/2005 Horvath

12sec MxP_OXSP_ETCH endpoint detection didn't work

b) Etch marks into Si

Lam5 recipe: 5003

1200A Si etch

9/7/2005 Horvath

Centura DPS_SI_ETCH

W#1 W#2 W#3 W#7 W#10

21sec 21sec 21sec 21sec 20sec

depth with ox 1600 (top) 1500 (top) 1580 (top) 1560 (top) 1410(top)

depth in Si 1360A 1340A 1350A 1320A 1170A

c) Photoresist strip

Matrix

Std. 2 min O2 ash

Measure PM depth with ASIQ

9/7/2005 Horvath

6

PAD OXIDATION / NITRIDE DEPOSITION

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

9/8/2005 Horvath

Processed in Tystar1, TCA

b) Std. clean wafers

Sink8 + Sink 6

Piranha + 25/1 HF until dewet

Include NCH, PCH

9/8/2005 Horvath, Vida

c) Dry oxidation

Tystar2, 2DRYOXA

Target = 250A       1000C, 21 min; 15 min N2 annealing

Measure oxide thickness on PCH, NCH

9/8/2005 Horvath, Vida

Tystar1, 1GATEOXA

NCH PCH

287 277 274 285 280  280 285 278 287 282

d) Nitride deposition

Tystar9, 9SNITA

Target = 2200A             (~ 65min @ 800C)

Do not include PCH, NCH.                          Measure nitride thickness

9/8/2005 Horvath, Vida

deposition rate 40A/min. deposition time: 56min

W#1 W#4 W#7 W#10

2434   2419   2480   2468   2427   2314   2269   2305   2321   2277   2189   2145   2169   2187   2137   2244   2200   2231   2245   2197

7

N-WELL PHOTO

ASML

Std. litho                Mask: NWELL           Oven bake 1 hr

9/12/2005 Horvath

Energy: 25mJ

8

NITRIDE ETCH

Centura MxP+       recipe: MXP_NITRIDE_ME

Monitor endpoint

Measure oxide thickness on every wafer.                           Make sure to have sufficient blocking for the following implant

9/13/2005 Horvath

MxP_NITRIDE_OE CH3F=20, Ar=50, O2=7, press=50mT pw=450W

Etch rate (A/min) W#1 W#4

3560   3550   3544   3628   3602   3378   3374   3336   3416   3450

Etch W#1 W#2 W#3 W#4 W#5 W#6 W#7 W#8 W#9 W#10

50sec 50sec 50sec 50sec 50sec 50sec 45sec 50sec 50sec 50sec

Oxide (T,C) 190 189        180 184        228 215        222 212        218 202        220 204        209 196        252 201        243 215        273 245

9

N-WELL IMPLANT

CORE Systems

Specie/Dose/Energy:  P, 1E13, 150keV

Include PCH

9/20/2005

10

NITRIDE REMOVAL

a) Photoresist strip

Matrix

Std. 2 min O2 ash

9/20/2005 Horvath, Vida

b) Std. clean wafers

Sink8 (MEMS)

Piranha

9/20/2005 Horvath, Vida

c) Nitride wet etch

Sink7

160C fresh phosphoric acid ~4 hours

9/20/2005 Horvath

Wet etch time: 150min oxide on Si 253A

d) Pad oxide wet etch

Sink8

5/1 BHF until dewet

Include PCH, NCH

9/20/2005 Horvath

11

PAD OXIDATION / NITRIDE DEPOSITION

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

9/21/2005 Horvath

b) Std. clean wafers

Sink8 + Sink 6

Piranha + 25/1 HF until dewet

Include NCH, PCH

9/21/2005 Horvath

c) Dry oxidation

Tystar2, 2DRYOXA

Target = 250A       1000C, 21 min; 15 min N2 annealing

Measure oxide thickness on PCH, NCH

9/21/2005 Horvath

NCH PCH

240 235 235 264 238  238 237 241 249 233

d) Nitride deposition

Tystar9, 9SNITA

Target = 2200A           (~ 65min @ 800C)

Do not include PCH, NCH                          Measure nitride thickness

9/21/2005 Horvath

deposition rate 40A/min. deposition time: 56min

W#10 W#1 mon#2

2467 2455 2413 2501 2464            2175 2146 2168 2147 2188            2552 2535 2606 2584 2557

12

P-WELL PHOTO

ASML

Std. litho                Mask: PWELL           Oven bake 1 hr

9/26/2005 Horvath

Energy: 19mJ

Problem with positioning 25 dies not exposed on the Left and Top side

13

NITRIDE ETCH

Centura MxP+       recipe: MXP_NITRIDE_ME

Monitor endpoint

Measure oxide thickness on every wafer.                           Make sure to have sufficient blocking for the following implant

9/29/2005 Horvath

MxP_NITRIDE_OE CH3F=20, Ar=50, O2=7, press=50mT pw=450W, expected etch rate: 3500A/min (see step8)

Etch rate       A/min (9/28/05) W#10             Etch rate        A/min (9/29/05)  Mon#1       Mon#2

1968 1828 1772 1946 1910          ---          ---          ---               ---          ---          ---            1058 1146 932 962 1010      998  1186  932 1048 992

Etch rate varies day by day nonuniform etch speed selectivity very low nit/ox=3/1 instead of 10/1

Oxide  W#1 W#3 W#4 W#5 W#6 W#7 W#8 W#9

146 130 143 117 141            121 167 171 120 163              85    99    96   ---   ---            157 189 147 151 159                119 138 134   ---   ---            130 163 153   ---   ---               NO OXIDE                            84  134  178  71 157

14

P-WELL IMPLANT

CORE Systems

Specie/Dose/Energy:  B, 5E12, 60keV

Include NCH

10/10/2005

15

NITRIDE REMOVAL

a) Photoresist strip

Matrix

Std. 2 min O2 ash

10/10/2005 Vida

b) Std. clean wafers

Sink8 (MEMS)

Piranha

10/10/2005 Vida

c) Nitride wet etch

Sink7

160C fresh phosphoric acid ~4 hours

10/11/2005 Vida

Wet etch time: 160min oxide on Si 120A

W#1 W#4 W#8

125 128  88 130 116            122  87   70 138 117            134 109  94 140 154

d) Pad oxide wet etch

Sink8

5/1 BHF until dewet

Include PCH, NCH

10/11/2005 Vida

Inspection under UV light: shadowy features at the edge of exposed area,    looks like Si overetch

16

WELL DRIVE-IN

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

10/12/2005 Horvath, Vida

b) Std. clean wafers

Sink8 + Sink 6

Piranha + 25/1 HF until dewet

Include NCH, PCH

10/12/2005 Horvath, Vida

c) Well drive-in

Tystar2, 2WELLDR

1100C, 150 min; 15 min N2 annealing

Measure oxide thickness

10/12/2005 Vida

Oxide W#1 W#4 W#8 W#10 NCH PCH

2038  2045  2044  2046  2040       2062  2047  2049  2054  2072         2071  2055  2051  2047  2049       2059  2053  2060  2041  2073       2071  2079  2086  2092  2079       2045  2012  2060  2062  2053

d) Oxide wet etch

Sink8

5/1 BHF until dewet

Measure Rs on PCH, NCH

10/12/2005 Horvath, Vida

approx. 2min etch

17

PAD OXIDATION / NITRIDE DEPOSITION

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

10/13/2005 Horvath, Vida

b) Std. clean wafers

Sink8 + Sink 6

Piranha + 25/1 HF until dewet

Include NCH, PCH      and 2 dummies

10/13/2005 Horvath, Vida

c) Dry oxidation

Tystar2, 2DRYOXA

Target = 250A       1000C, 21 min; 15 min N2 annealing

Measure oxide thickness on NCH

10/13/2005 Horvath, Vida

NCH

275,278,291,295,264

d) Nitride deposition

Tystar9, 9SNITA

Target = 2200A           (~ 65min @ 800C)

Include only PCH and the dummies.                          Measure nitride thickness

10/13/2005 Horvath, Vida

First run after Tystar9 maintenance, lower deposition rate, 33A/min

W#1 W#10 PCH

1874 1839 1876 1868 1870            1789 1728 1739 1750 1761             1899 1896 1938 1916 1907

18

ACTIVE AREA PHOTO

ASML

Std. litho                Mask: ACTIVE           Use BARC if needed.   UVBAKE program U

10/25/2005 Horvath, Vida

Energy: 20mJ

19

NITRIDE ETCH

Centura MxP+       recipe: MXP_NITRIDE_ME

Monitor endpoint, allow some over etch

Measure oxide thickness on each wafer on the ACT measurement area

11/07/2005 Vida

Lam1 tried as backup, bad uniformity of etching 4 wafers processed in Lam1, W#4, W#7, W#8, W#10

Oxide W#4 W#7 W#8 W#10

145 222  170  245 180,   236 175 <100 222 253,  200 193 216 236 <100,   263 316  277  232  221

both wafers overetched in centura!

11/17/2005 Horvath, Vida

6 wafer processed in Centura_MxP, Program: MxP_Nitride_OE,              Etch rate: 900-1200A/min

W#1 W#2 W#3 W#5 W#6 W#9

191 155 165 200 221,  228 157 134 208 187,  254 226 238 241 261,  215 111 149 209 212,  264 236 239 266 260, 150 196 202 129 245

20

P-WELL FIELD IMPLANT PHOTO

a) Photoresist strip

Matrix

Std. 2 min O2 ash

11/18/2005 Horvath, Vida

PR ashing was made in Technics-C

time: 4min, process gas: O2

b) Std. clean wafers

Sink8

Piranha

11/18/2005, Vida

c) Lithography

ASML

Std. litho                Mask: PFIELD           Oven bake 1 hr

With thicker nitride film at step 17 (sufficient implant blocking), PFIELD mask could be substituted with PWELL mask

11/18/2005, Vida

PFIELD mask, Illumination Energy: 20mJ

21

P-WELL FIELD IMPLANT

CORE Systems

Specie/Dose/Energy:  B, 2E13, 80keV

11/25/2005

22

LOCOS OXIDATION

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

11/25/2005, Vida

b) Photoresist strip

Matrix

Std. 2 min O2 ash

11/26/2005, Vida

c) Std. clean wafers

Sink8 + Sink 6

Piranha + 10 sec dip in 25/1 HF

Include NCH, PCH

11/26/2005, Vida

d) Wet oxidation

Tystar2, 2WETOXA

Target = 5500A       1000C, 120 min; 20 min N2 annealing

Measure oxide thickness on NCH + 3 work wafers

11/26/2005, Vida

W#1 W#2 W#3 W#4 W#5 W#6 W#7 W#8 W#9 W#10 NCH

5144 5185 5227 5190 5185,           5430 5510 5446 5672 5377,           5440 5564 5396 5538 5516,           5310 5568 5392 5703 5458,           5447 5468 5367 5636 5421,           5493 5675 5599 5680 5684,            5235 5355 5336 5353 5383,           5354 5441 5456 5469 5379,           5402 5633 5494 5466 5534,             5340 5640 5513 5500 5564,           5137 5258 5259 5195 5186

23

NITRIDE REMOVAL / PAD OXIDE REMOVAL

a) Oxide wet etch

Sink 6

10/1 HF for 60 sec

Etch thin oxide layer off from the top of the nitride film.           Include PCH.

11/28/2005, Vida

b) Nitride wet etch

Sink 7

160C fresh phosphoric acid ~4 hours

Measure pad oxide on ACT measurenet area to make sure nitride is gone

11/29/2005, Vida

Etch time: 150min,          etch rate: 16A/min

ACTIVE W#1 W#6 W#10 PCH

176 184 207 191 190,  194 199 213 204 204,  161 179 186 169 164,    -    -    -    -    -

LOCOS W#1 W#6 W#10

4411 4465 4609 4522 4509,            4784 5038 4990 5028 5008,           4642 5000 4898 4860 4899

c) Oxide wet etch

Sink 6

10/1 HF for 60 sec  (PCH dewet)

Etch pad oxide

11/29/2005, Vida

d) Oxide wet etch on NCH

Sink7

Fresh 5/1 BHF until dewet

Remove LOCOS from NCH

11/29/2005, Vida

24

SACRIFICIAL OXIDATION

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

11/29/2005, Vida

b) Std. clean wafers

Sink 6

Piranha + 10 sec dip into 25/1 HF

Include NCH, PCH

11/29/2005, Vida

c) Dry oxidation

Tystar2, 2DRYOXA

Target = 250A       900C, 40 min;                1 sec (meaning zero)         N2 annealing

Measure oxide thickness on ACT measurement area

11/29/2005, Vida

Oxide thickness measured by NanoDUV

W#1 W#2 W#3 W#4 W#5 W#6 W#7 W#8 W#9 W#10 NCH PCH

169 157 151 154 152,  172 171 177 186 194,  190 174 199 223 192,  240 210 201 195 203,  189 201 192 200 206,  203 199 195 214 230,  209 190 200 215 200,  162 160 205 202 204,  159 163 203 210 205,  161 158 144 155 145,  165 169 167 155 171,  169 163 160 159 172

25

SCREEN OXIDATION

a) TLC clean

Tystar2, 2TLCA

2 hrs of cleaning

11/30/2005, Vida

b) Std. clean wafers

Sink 6

Piranha +  25/1 HF dip until NCH, PCH dewet

Include NCH, PCH

11/30/2005, Vida

c) Dry oxidation

Tystar2, 2DRYOXA

Target = 250A       900C, 40 min; 15 min N2 annealing

Measure oxide thickness on ACT measurement area

11/30/2005, Vida

Real oxidation time: 43min Oxide thickness measured by NanoDUV

W#1 W#2 W#3 W#4 W#5 W#6 W#7 W#8 W#9 W#10 NCH PCH

174 173 166 175 176,                         180 181 186 199 204,                      192 180 195 192 196,                      189 181 176 186 187,                      183 180 179 222 233,                      189 194 191    -    -    ,                      194 191 185    -    -    ,                     196 187 199    -    -    ,                        173 175 170    -    -    ,                       184 177 174    -    -    ,                       163 163 158 161 175,                        174 174 177 160 181

26

NMOS Vt IMPLANT PHOTO

ASML

Std. litho                Mask: PWELL           UVBAKE program J

12/09/05,   Vida

27

NMOS Vt IMPLANT

CORE Systems

Specie/Dose/Energy:  BF2, 4E12, 50keV

Include NCH

12/12/2005 Vida

NMOS Vt implant split!!!                       W#1-W#5: BF2, 4E12, 50keV                            W#6 - W#10, NCH:                  BF2, 3E12, 50keV

28

PMOS Vt IMPLANT PHOTO

a) Photoresist strip

Matrix

Std. 2 min O2 ash

12/07/05,   Vida

b) Std. clean wafers

Sink8

Piranha

12/07/2005, Vida

c) Lithography

ASML

Std. litho                Mask: NWELL           UVBAKE program J

12/01/2005, Horvath

PMOS Vt implant photo was made first

29

PMOS Vt IMPLANT

CORE Systems

Specie/Dose/Energy:  P, 2E12, 30keV

Include PCH

12/01/05    Vida

30

GATE OXIDATON / POLY DEPOSITION

a) TLC clean

Tystar1, 1TLCA

2 hrs of cleaning

Reserve poly deposition tube

12/15/2005, Horvath

Process done in Tystar1 with program 1TCA

b) Photoresist strip

Matrix

Std. 2 min O2 ash

12/15/2005, Horvath

c) Std. clean wafers

Sink8 + Sink 6

Piranha + dip in 25/1 HF until NCH, PCH dewet

Include NCH, PCH, Tox, Tpoly1, Tpoly2      p-type prime monitor wafers

12/15/2005, Horvath

c) Gate oxidation

Tystar 1, 1THIN-OX

Target = 80A          850C, 30 min oxidation; 900C, 30 min N2 annea (RED: oxide thickness?)

Include NCH, PCH, Tox, Tpoly1, Tpoly2, plus 3 test dummies. Note: ALMACK Step25 in furnace process unless the pre-oxidation temp. is 450C

12/16/2005, Horvath

d) Poly-Si depostion

Tystar 10, 10SUPLYA,

Target = 2500A          Dep. time ~ 28 min

Include Tpoly1, Tpoly2 and the test dummies

12/16/2005, Horvath

Deposition time: 24min

Tpoly1    2711  2795  2957  2848  2735      Tpoly2    2452  2475  2508  2482  2450

e) Measurements

Sopra, Rudolph

Measure oxide thickness on Tox

12/16/2005, Horvath

Measured with Sopra

Tox = 75.5A

SCA

Measure Dit, Qox, Nsc, Ts on Tox

12/16/2005, Horvath

Nsc = 3.2E14   Qox = 1E11

Dit = 3.5E10  Ts = 320

Nanospec

Measure poly thickness on ACT+POLY measurement area

12/16/2005, Horvath

4PTPRB

Strip oxide from NCH and PCH;                         measure Rs

12/16/2005, Horvath

31

POLY GATE PHOTO

ASML

Std. litho with BARC                Mask: POLY           UVBAKE program U

Include poly test dummies

12/20/2005, Horvath

3750 RPM for 30sec        Softbake: 205C for 60sec Standard coat. W/O HMDS

ASML matrix measurement                          mean energy: 21mJ step 1mJ                        mean focus: 0micron step 0.1micron                             best values at 21mJ -0.4micron

32

POLY-Si ETCH

a) Poly etch

Lam5 recipe 5003

Monitor endpoint,          ~ 50% over etch

Etch through BARC + poly. Check overetch recipe in cmos161 process

12/21/2005, Horvath

Etch rates measured on dummies (A/min)   Dummy1    3720  3878  3630  3724  3726      Dummy2    3788  3992  3884  3912  3832

b) Photoresist strip

Matrix

Std. 2 min O2 ash

12/21/2005, Horvath

b) Std. clean wafers

Sink 8

Piranha

Check Poly-Si lines with SEM

01/02/2006, Horvath

Additional step should be inserted here: Sink7 1/100 HF dip for 1min to remove polymers formed during Lam5 poly etch

33

PMOS LDD IMPLANT PHOTO

ASML

Std. litho                Mask: P+S/D           UVBAKE program J

01/03/2006, Horvath

Mask: PSELECT        Energy: 22mJ,               Focus offset: 1micron

34

PMOS LDD IMPLANT

CORE Systems

Specie/Dose/Energy:  BF2, 5E13, 10keV             +7 deg. tilt                        @ 0 orientation;                      BF2, 5E13, 10keV                       -7 deg. tilt                              @ 180 orientation

Include PCH, Tpoly1

01/03/2006, Horvath