Semiconductor Photoresist Coat and Develop Processing

Semiconductor Photolithography Process, spin-coater, bake, and develop
Advanced Wafer Coat, Bake & Develop.

S-Cubed’s 30 years of building photoresist processing equipment for the semiconductor industry, have culminated in its latest set of products, the Scene 8tm, and the Scene 12tm . Today’s modern tools are much more flexible and reliable and provide far better process uniformities and cleanliness. The most advanced are tools like our Scene 12tm , can provide multiple process capabilities in a smaller form factor than any other Photoresist processing station in the industry.  The flexibility of the Scene 12tm is such that all critical pararameters are easily programmable and held to tight tolerance by advanced electromechanical control systems.

  • Programmable dispense heights and position.
  • Servo rather than stepper motor motion control assures closed feedback loop for extreme process precision.
  • Precise control of spin conditions for both Acceleration and spin velocity within a single revolution in absolute terms.
  • Interlocked spin and dispense control means for best uniformity. Constant Aerial Timing (CAT) CAT dispense is a unique capability to S-Cubed.
  • Simple programmable control of exhaust conditions in the spin bowl during dispense and acceleration
  • Self-cleaning hot plates with fixed and programmable proximity bake.
    (NOTE:  Precision motion control of wafer/hotplate distance for temp rate control is especially helpful for thick polymer films and pyroelectric substrates)
  • Self cleaning spin bowls for polymer application

Due to the multiplicity of processes going on in a coater-developer the wafer handling techniques must be highly reliable. The latest techniques in robotics and mechatronics involving closed loop brushless servo motors are employed.

Since the wafers are processed by spinning on a vacuum chuck the tool should have a means of ensuring that the wafer is well centered on the spin axis. This “set up” procedure can be time consuming so S-cubed Photoresist processing tools have the capability built into the tool to learn the centering of the wafer at each spin axis is an important factor in both reducing system installation time and ensuring day to day precision wafer handling.

Choose our advanced processing equipment for excellent photoresist bake and photoresist develop processing.

Coating Uniformity

Because of the careful control of spin and acceleration provided by the Scene 12/8 family of tools, coating uniformity is extraordinary.

S-Cubed Photoresist Coating Uniformity
Using the Scene 12, coating uniformity varies by less than .5% using BCB


The Photoresist Develop Process

The develop process will be either aqueous based (most frequently TMAH) or solvent base depending on the photoresist polymer chemistry. As the aqueous develop is essentially an etch, it is important that corrosion rather than erosion be the only process so that develop “hot spots” can be avoided. Hot spots will very adversely effect develop uniformity. A “zero impact” dispense means that can very rapidly build a puddle without creating hot spots must be used. To further improve uniformity, develop rate and reduce developer consumption the tool should provide user programmable agitation. Agitation during the puddle develop of aqueous based develop process provide refreshment of reactant at the photoresist/developer boundary layer which provides the benefits of uniformity, consumption and rate.

Photoresist Coating Unifomity of S-Cubed Semiconductor Photoresist Process.
Coating uniformity of SPR 220 on a 6 inch, 150mm wafer

For solvent based develop in which a gel like material is created by S-Cubed Polyimide Wafer Spin Coating With Bake and Developthe action of the solvent, a needle like programmable stream provides the desired removal while maintaining control of the fluid.

Our Scene 12 system uses a unique dual nozzle design. Maintaining the fluid as a stream is a far superior solution than the spray of droplets typically used by other semiconductor photoresist processing tools.

The dual stream design has proven to be both more effective at removal, and easier and less costly  to control.

For more information on our Semiconductor Photoresist Coater/Developer processors, call the S-Cubed engineering team today.