Photolithography Machine Control System

Ben Conrad and Mark EdwardsProjects in Computer

Engineering IIDecember 9, 2003

System Overview – Solitec 8360

Used in the photolithography process to evenly apply chemicals to wafers25 200mm wafer capacityMain components: Wafer input cartridge, wafer output cartridge, spin chuck, bake chuck, system tray

Spin Chuck  Vacuum Tube

Bake Chuck  Vacuum Tube

Wafer Output Cartridge

(25 wafers)

Wafer Input Cartridge

(25 wafers)

 

      

System Overview – Solitec 8360

           Wafer Load

Processing on Spin Chuck Bake on Bake ChuckMultipass Mode CheckWafer Egress

System Overview – Solitec 8360

System Controller

Provides an interface between the operator and the control unit. Formats data for display to the user Interprets and forwards user requests and

input to the control unit

Function: DEV1 Time: 25.2 SECRCP#: 3 Speed: 256 RPM

1 2 3 ESC

PREWET RINSE N2 4 5 6 SCH STOP

7 8 9 Inter lock

0 ENTR

Program RunEnd of Recipe Inter Lock

DEV1

System Controller Cont’Control the system’s mode of operationThree operating modes Service: manual system operation Program: writing and editing of recipes Run: recipe execution/system calibration

Recipe Commands

Seven Executable Commands PREWET: Dispense de-ionized(DI) water Dispense DEV#1: Dispense developer solution RINSE: Dispenses DI water to clean wafer N2: Dispenses Stream of Nitrogen (N2) SPIN: Spin Dry the wafer WAIT: Static delay option.

Parameters Time: .1 – 999.9 sec. (.1 second resolution) Speed: 0-7,999 RPM Ramp: 0 – 40 KRPM/s

Motivation

Old controller was corroded; less elements in our design -> more reliableCost savings to customer, Dr. Raisanen, associate director of RIT’s fabOur design ~$350, vs. $3k-$15k

Feasibility

Motor Control Board will be reused – no digital controller need be implementedOther than 3 analog, all I/0 are TTL digital logic, no conditioning neededSensors have been tested and functionality for most is verifiedTiming Budget: Asynchronous System

System Design- High Level

The STD Bus will be replaced with a HC12-s microcontrollerA HC11 will be connected to the HC12 via SPI protocol to handle UICustom Circuits are created to multiplex numerous I/0 lines to the HC12’s limited pins

System Design – High Level

HC12

A

B

P

S

A/D

50 PinInput Cable

50 PinOut Cable

KeypadandLCD

Servo Board

3 16-bit serial in, parallel out shift registers for output= 48 output bits

2 16-bit parallel in, serial out shift registers for input= 32 input bits

1 16-bit serial in, parallel out shifter

2 8-bit DACs

HC 11

 

 

System Controller Hardware

Input 4x4 Matrix keypad

Interrupt driven

SPI bus Three wire interface to digital controller Used to communicate status and display

information

System Controller H/W Cont’

Output 40x4 Character LCD display

SPI bus Forwards user input the control unit.

Status Lights Run mode Program mode End of Processing Interlock

System Controller H/W Cont’

Processing unit Motorola 68HC11

512 bytes RAM, 512 bytes EEPROM Synchronous peripheral interface (SPI) Real time interrupt circuit

Data aggregation Distribute workload

System Controller Schematic

KB(ROW1)

C10

1uf

C121uf

KB(ROW4)

VCC

KB(COL2)

VCC

C6??

R347k

C11uf

LCD( data 2)

Serial(RX)

VCC

LCD(data 4)C527pf

LCD(data 7)

R547k

C11

1uf

LCD(RS)

LCD(E2)

C91uf

KB(ROW3)

SPI(MOSI)

J2

MODEB

12

U4

MC68HC11E9

5251

3130292827

4241403938373635

910111213141516

202122232425

5

26

87

17

19

18

2

343332

4345474944464850

436

VRHVRL

PA3PA4PA5PA6PA7

PB0PB1PB2PB3PB4PB5PB6PB7

PC0PC1PC2PC3PC4PC5PC6PC7

PD0PD1PD2PD3PD4PD5

E

VDD

XTEX

RST

IRQ

XIRQ

MODB

PA0PA1PA2

PE0PE1PE2PE3PE4PE5PE6PE7

ASMODA

R/W

KB(COL1)

KB(COL4)

LCD(Data 1)

C710*C6

LCD(data 6)

U2

MAX232

1345

1615

26

129

1110

138

147

C1+C1-C2+C2-

VC

CG

NDV+

V-

R1OUTR2OUT

T1INT2IN

R1INR2IN

T1OUTT2OUT

LCD(E1)

VCC

SPI(MISO)

C81uf

R447k

Y1

8MHz

C21uf

KB(ROW2)

J1MODEA

12

R21k

R1 10M

KB(ROW5

LCD(data 3)

KB(COL3)

C3.1uf

VCC

C427pf

LCD(data 5)

LCD(data 0)

VCC

LCD(R/W)

Serial(TX)

R6

47k

U3

74C923

67

14

1918171615

1312345

1211

98

OSCKBM

OE

DOADOBDOCDODDOE

DAY1Y2Y3Y4Y5

X1X2X3X4

VCC

System Design – System I/O

Shows the detailed HC-12 Control Unit I/O connections

System Design – System I/O

B0

HC12- A3

B1

16 Bits to Cable (16-31)

8 Bits to DAC1

A4

Serial Out to HC12

B2

HC12- B4

U5

74F676

4

5

2

6

1

78910111314151617181920212223

SI

MODE

CLK

SO

CS

P0P1P2P3P4P5P6P7P8P9

P10P11P12P13P14P15

HC12-A116 Bits to Cable (0-15)

HC12- B2

B3

HC12- A7

8 Bits to DAC0

B4

Serial Out to HC12

B5

HC12-A2

HC12-A5

U3

74F675A

4

3

5

7891011131415

1617181920212223

6

1

2

SI

R/W

STCP

Q0Q1Q2Q3Q4Q5Q6Q7

Q8Q9

Q10Q11Q12Q13Q14Q15

SO

CS

SHCP

Ben Conrad, Mark Edwards

A3

A6

Schematic: Shift Register to HC12 Connections

16 input Bits (0-15)

HC12- A6

32 Input Bits

A7

U2

74F675A

4

3

5

7891011131415

1617181920212223

6

1

2

SI

R/W

STCP

Q0Q1Q2Q3Q4Q5Q6Q7

Q8Q9

Q10Q11Q12Q13Q14Q15

SO

CS

SHCP

U2

74F675A

4

3

5

7891011131415

1617181920212223

6

1

2

SI

R/W

STCP

Q0Q1Q2Q3Q4Q5Q6Q7

Q8Q9

Q10Q11Q12Q13Q14Q15

SO

CS

SHCP

HC12-A4

16 input Bits (16-31)

A2

HC12- B3

A1

U6

74F676

4

5

2

6

1

78910111314151617181920212223

SI

MODE

CLK

SO

CS

P0P1P2P3P4P5P6P7P8P9

P10P11P12P13P14P15

HC12-A0A0

U2

74F675A

4

3

5

7891011131415

1617181920212223

6

1

2

SI

R/W

STCP

Q0Q1Q2Q3Q4Q5Q6Q7

Q8Q9

Q10Q11Q12Q13Q14Q15

SO

CS

SHCP

HC12- B5

HC12 - P7

16 Bits to Cable (32-47)

HC12 - P6

48 Output Bits

A5

System Software DesignRun mode flowchart

System Software Design

Task control block(TCB) Tracks the processing of a single wafer

Field Size (bytes) DescriptionRECIPE_START 2 Address of the current recipeCUR_CMD_ADDRESS 2 Address of the current command being executedBAKE_TIME 2 Length of time to heat a wafer on heat chuckCURRENT_BK_TIME 2 Amount of time that the wafer on the heat chuck has been baking. SPIN_TIME 2 Amount of time the wafer has remaining on the spin chuckSPIN_VELOCITY 2 Rotational velocity of the spin chuck for the current recipe stepSPIN_ACCELERATION 1 Motor's acceleration up to the spin the chuck's spin velocityOPERATION 1 actual recipe stepSTATUS 2 Program status flagCURRENT_SPEED 1 Actual speed of the spin chuckDAC_OUT 2 Byte to be written to DACSENSOR_IN 4 Storage for data read from input registersSENSOR_OUT 6 Storage for data to be written to output registers

TCB

Already Completed

Parts ordered and receivedHardware schematicsSoftware flowchartsTask control designSensor/System tests

Expected Difficulties

Unreliability of mechanical systemNo ability to completely test systemServo control board - analog signalsOverall system complexity