ASML EUV LITHOGRAPHY SYSTEM / PRODUCTION AND OPERATION MANUAL
DOC NO. TN-1986-EUV REV. A

1. GENERAL DESCRIPTION

This manual describes the construction and operation of an Extreme Ultraviolet (EUV) lithography system. The system prints the finest circuit patterns found in modern computer chips. Read this section before operating either trainer.

FIGURE 1-1. SIMPLIFIED SIGNAL PATH. LIGHT TRAVELS LEFT TO RIGHT.

1.1 PURPOSE

  1. The system exposes a light-sensitive wafer through a patterned mask.
  2. The exposure copies the mask pattern onto the wafer at very small scale.
  3. Repeated exposure across the wafer builds the layers of a microchip.
NOTE

EUV light has a wavelength of 13.5 nanometres. That is roughly 14 times shorter than the light used by earlier machines. Shorter light prints smaller features. Smaller features mean faster, cheaper chips.

1.2 PRINCIPAL ASSEMBLIES

ITEMASSEMBLYFUNCTION
ALIGHT SOURCEProduces the 13.5 nm EUV light.
BILLUMINATORShapes and directs light onto the mask.
CPROJECTION OPTICSFocuses the mask pattern onto the wafer.
DWAFER STAGEMoves the wafer with sub-nanometre precision.
EVACUUM FRAMEHolds all optics in a clean vacuum.

2. THEORY OF OPERATION

2.1 HOW THE LIGHT IS MADE

  1. A generator fires molten tin droplets, about 50,000 each second.
  2. A high-power laser strikes each droplet twice. The first pulse flattens it. The second pulse turns it into a hot plasma.
  3. The plasma glows with 13.5 nm EUV light.
  4. A curved collector mirror gathers the light and sends it onward.
WARNING

EUV light is absorbed by air, glass, and skin. It can injure the eyes and damage tissue. The entire light path runs inside a sealed vacuum. Never break the vacuum while the source is armed.

2.2 WHY MIRRORS, NOT LENSES

No known glass lets EUV light pass through it. The system therefore steers light with mirrors only. Each mirror is built from about 50 alternating layers of molybdenum and silicon. These layers reflect roughly 70 percent of the EUV light. The rest is lost as heat.

CAUTION

Every extra mirror throws away light. A path with too many reflections will not expose the wafer. Keep the number of bounces low. This rule is the basis of the LIGHT PATH TRAINER in Section 3.

2.3 SCANNING THE WAFER

  1. The mask and the wafer move at the same time, in opposite directions.
  2. They stay aligned to within a fraction of a nanometre.
  3. The system prints one small field, steps over, and prints the next.
  4. A finished wafer holds many identical chips.

3. PRODUCTION SEQUENCE

One machine is not built in one place. Thousands of modules arrive from suppliers across the world. They are assembled, aligned, and tested before shipping. The FACTORY TRAINER in Section 2 models this flow.

3.1 SUPPLY OF MODULES

MODULETYPICAL ORIGINBUILT IN TRAINER FROM
MIRROR BLANKUltra-low-expansion glassGLASS + COATING
PROJECTION OPTICSPrecision optics worksMIRROR + FRAME
WAFER STAGEPrecision motion worksCHIPS + FRAME
EUV SYSTEMFinal assembly hallOPTICS + STAGE

3.2 ASSEMBLY RULE

  1. Feed the correct raw material to each machine.
  2. A machine runs only when all of its inputs are present.
  3. Route finished parts to the ASSEMBLY HUB.
  4. The hub ships one complete EUV SYSTEM when it has all parts.
NOTE

The frame material feeds two different machines. Plan the belts so both receive a steady supply. Starving one machine stalls the whole line.

3.3 DELIVERY AND INSTALLATION

  1. A complete system weighs about as much as two large trucks.
  2. It ships disassembled in roughly 40 freight containers.
  3. Several cargo aircraft may be used for the fastest deliveries.
  4. Engineers rebuild and align the system inside the customer plant.

GO TO SECTION 2 TO BEGIN THE FACTORY TRAINER.

SEC 2 / FACTORY TRAINER OBJECTIVE: BUILD AND SHIP 1 EUV SYSTEM
OUTPUT DIR: EAST ELAPSED: 0.0 s
SEC 3 / LIGHT PATH TRAINER ROUTE THE 13.5 nm BEAM TO THE WAFER
BEAM INTENSITY 100%

4. DATA PLATE AND GLOSSARY

4.1 SYSTEM DATA

PARAMETERVALUE
LIGHT WAVELENGTH13.5 nanometres (EUV)
TIN DROPLETSAbout 50,000 per second
MIRROR REFLECTIVITYAbout 70 percent each
MIRROR LAYERSAbout 50 molybdenum and silicon pairs
OPERATING ENVIRONMENTVacuum
STAGE PRECISIONFraction of a nanometre

4.2 GLOSSARY

TERMMEANING
EUVExtreme Ultraviolet. Very short wavelength light.
LITHOGRAPHYPrinting a pattern with light.
PLASMASuperheated gas that glows with EUV light.
RETICLEThe patterned mask that is copied.
WAFERThe silicon disc that becomes chips.
OVERLAYHow well one printed layer lines up with the last.
NOTE

This is a teaching model. Values are rounded for clarity and are not service data. Refer to the manufacturer for exact figures.