Photolithography area

All steps of the photolithographic process (dehydration and HMDS deposition, resin deposition and spreading, UV exposure, resin development, and inspection…) are performed in this area.

The main characteristics of the area:

  • The lighting in this room is filtered (yellow light) to avoid undesirable exposure of the resin (ultraviolet sensitive).
  • The surface area is 55m² and the height is 3.5m.
  • It is class 10 according to US Fed Std 209E or equivalent to class 4 according to ISO.
  • It is conditioned by a temperature of 21°C and a humidity of 43%.
  • The area is physically separated by partitions and doors to avoid cross-pollution between it and other areas classified as upper.

Equipment available in the photolithography area

Lt-Gen DSW 8000 Stepper

The equipment is used to align and expose the mask image and reduce it on the plate. Ultraviolet radiation is produced by a mercury lamp with a main line of 365 nm (i-line).

  • I-Line with 1635i Tropel lens (5x, 0.35NA) with λ= 365 nm.
  • Environmental chamber 6630S and atmospheric compensation system.
  • Global overlay system: ± 0.25μm.
  • Local overlay system: ± 0.15μm.
  • Interchangeable Chuck system and 10-stage reticle management system.
  • Intensity Qualifier (IQ) and quartz reticules: 5 “x 5”.
  • Automatic plate loader AHW (Auto Wafer Handler).
  • Maximus 1000 light source (Provides 365 watts of continuous light)
  • TMC isolation platform (vibration isolation).
  • Metrology system SMART SET.
  • Resolution: 0.8 μm.
  • Focus Depth: 3 μm.
  • Overlay: ±0.3 μm or more.
  • Throughput: 35 Plates per hour, and 25 Plates per batch.
  • Insert size: 150mm (6 inch).

SVG8800 dual Coater & Developer Track.

The SVG 8800 is production equipment that automatically and quickly prepares batches of platelets for photolithography. It is used to coat substrates with resins and to develop them automatically.

The SVG 8800 machine performs the following functions:

  • Deposition and development of photosensitive resins.
  • Heat treatments (pre annealing, annealing after EPB exposure, hard annealing).
  • Preparation of wafers free of photosensitive resin bulges near the edge of the wafers (Edge bead removal, EBR).
  • The equipment consists of two independent lines (Track):
Receiver cassette Chill plate
21-23 °C
Hot plate
(Hard Bake)
Developer Chill plate
21-23 °C
Hot plate (PEB) Sender cassette
Sender cassette Coater Hot plate
(soft bake)
Chill plate
21-23 °C

HMDS YES 6112 Oven

This equipment is intended for the treatment and preparation of the surface of the wafer substrate. It is a system that combines complete dehydration of the wafer surface with priming (deposition of a thin layer of the HMDS adhesion promoter).
Wafer surface preparation is a two-step process performed in a closed chamber:

  • The first step is dehydration: the plate is heated for 1 or 2 minutes in the preparation chamber to a temperature of 150°C and a pressure of 1 torr.
  • The second step is a deposition process called the “primer”: a thin layer of HMDS is deposited. This promotes adhesion between the organic resin and silicon (or the inorganic silicon compound).

Possible services in the photolithography area

Preparation of the wafer substrate

  • Deposit of the adhesion promoter HMDS (HexaMethylDiSilazane).

Deposition and spreading of the photosensitive resin (spin coating)

  • Type of resin: HIPR 6512, HIPR517.

Alignment and Exposure of Photosensitive Resin with UV/I-line 365 μm
Resin development

  • The developer (OPD 4262 “TMAH”) tetra-methyl-ammonium hydroxide