2 - M N-Well CMOS Process Flow: TCAD: Process and Device Simulation
2 - M N-Well CMOS Process Flow: TCAD: Process and Device Simulation
2 - M N-Well CMOS Process Flow: TCAD: Process and Device Simulation
X. ZHOU © 1997
Mask for the 2–µm N-well CMOS Process
TCAD: Process and Device Simulation N-well CMOS Process Flow
Pattern
X. ZHOU 2 © 1997
1-D Cutline of the Mask
TCAD: Process and Device Simulation N-well CMOS Process Flow
Mask Field
NWELL dark
ACTIVE clear
POLY1 clear
METAL clear
CONTACT dark
X. ZHOU 3 © 1997
2–µm N-well CMOS Process Steps
TCAD: Process and Device Simulation N-well CMOS Process Flow
X. ZHOU 4 © 1997
2–µm CMOS Process Flow
TCAD: Process and Device Simulation N-well CMOS Process Flow
SiO
2. Initial oxidation: 2
X. ZHOU 5 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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UV
Mask: NWELL
+PR +PR
Deposit positive photoresist (+PR)
Masking
Exposure
Development
X. ZHOU 6 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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I -P
Implant P
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X. ZHOU 7 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
Target: xj = 3.4 µm
8. Oxide etch:
Strip all SiO2
X. ZHOU 8 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
(∆tSiN = ? See: 13 – 15 )
X. ZHOU 9 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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11. Active photolithography:
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UV
Mask: ACTIVE +PR +PR
+PR
Deposit positive photoresist
Masking
Exposure
Development
X. ZHOU 10 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
X. ZHOU 11 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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13. Field implant photolithography:
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UV
(Photoresist-on-photoresist process)
+PR2 +PR2
Mask: Reverse of NWELL
Deposit positive photoresist
Masking
Exposure
Development
X. ZHOU 12 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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B
Implant B
Dose: 1.5×1013 cm–2
Energy: 70 KeV oooooo
X. ZHOU 13 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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13 Field implant photolithography:
UV
Mask: NWELL
–PR –PR
Deposit negative photoresist +PR → –PR +PR → –PR
Masking
Exposure
Development
X. ZHOU 14 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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14 Field implant:
B
Implant B
Dose: 1.5×1013 cm–2 oooooo
Energy: 70 KeV
15 Photoresist removal:
X. ZHOU 15 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
X. ZHOU 16 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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2
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19. Threshold implant: I -B
X. ZHOU 17 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
SiO SiO
21. Gate oxidation: 2 2
X. ZHOU 18 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
Poly
22. Poly-Si deposition:
Deposit polysilicon: 4500 Å
P-doped: 1020 cm–3
Temperature: 610 °C
X. ZHOU 19 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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23. Gate definition:
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UV
Mask: POLY1
+PR +PR
Deposit positive photoresist
Masking
Exposure
Development
X. ZHOU 20 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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UV
Mask: NWELL
Deposit negative photoresist –PR –PR
Masking
Exposure
Development
X. ZHOU 21 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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I -As
Implant As
•••••••••••
Dose: 5×1015 cm–2
Energy: 130 KeV
(Gaussian)
X. ZHOU 22 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
Target: xj = 0.35 µm
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UV
Mask: NWELL
Deposit positive photoresist +PR +PR
Masking
Exposure
Development
X. ZHOU 23 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
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Implant B
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Dose: 5×1015 cm–2
Energy: 40 KeV
Target: xj = 0.55 µm
X. ZHOU 24 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
X. ZHOU 25 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
UV
33. Contact photolithography:
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Mask: CONTACT
+PR
Deposit positive photoresist
Masking
Exposure
Development
X. ZHOU 26 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
35. Metallization: Al
X. ZHOU 27 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
UV
36. Metal photolithography:
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Mask: METAL
+PR
Deposit positive photoresist +PR +PR
Masking
Exposure
Development
X. ZHOU 28 © 1997
2–µm CMOS Process Flow (Cont’d)
TCAD: Process and Device Simulation N-well CMOS Process Flow
X. ZHOU 29 © 1997