First Mask: provides a quick wafer throughput without alignment. The program skips the break for alignment after wedge error compensation and exposure takes place immediately after the wafer has reached the exposure distance.
Manual Alignment: stops for "Manual Alignment" prior to exposure. The stage stops at the alignment distance and provides the possibility for mask-to-wafer alignment.
Assisted Alignment: provides a video based pattern recognition system for assistance of manual alignment
Auto AL not available
Flood Exposure: exposes the whole wafer without a mask. The exposure can be started from the initial state independent if a mask (and mask holder) is loaded or not.
Test Exposure: provides multiple exposure with varying exposure times on a single wafer.
Type:
TSA, Top-Side Alignment
BSA, Back-Side Alignment
Illumination: selects the desired illumination combined with the microscope. (e.g. TSA microscope + BSA ext. => transmitted light from bottom side)
TSA, Top-Side Alignment
BSA, Back-Side Alignment
ext. TSA
ext. BSA
AL: Alignment Gap is the gap between mask and wafer used for alignment of mask to wafer.
Objective: Objective lens of microscope
5x and 10x object lenses are available
Choose and move the object lens manually if top-side (front-side) alignment is carried out, according to the recipe set up.
1.2 Alignment Positions Tab
Different microscope positions are displayed or can be programmed within this page.
1.3 Exposure Tab
Mask Holder: A selection of customized mask holders is listed.
157288 maskholder: Various sizes of mask holder
107110 maskholder: 5" x 5" mask holder
Chuck: A choice of customized chucks is listed.
107167 chuck: 4" wafer chuck
200664 chuck: A small size of sample chuck
WEC: Wedge Error Compensation
Mode: Select either WEC with (proximity) or without (contact) spacers between mask and wafer.
WEC Offset [μm]: The programmed offset is added to the alignment gap. For example an offset of +10μm increases the alignment gap, an offset of -10μm decreases the alignment gap by 10μm.
Enable NCG: NCG - Non Contact Gap Setting provides wedge error compensation without touching the wafer surface
Wafer Thick: If NCG is selected the wafer thickness (in μm) must be programmed.
Exposure:
Mode
Constant Power exposes the wafer while the electrical Power to the lamp stays constant. The Exposure Time is defined in the recipe. Intensity fluctuations may occur.
Constant Dose keeps the "dose" (product of light intensity and time) constant. The light intensity is checked by a sensor and the exposure time is adjusted automatically.
Split Exposure: During Constant Power the light can be switched On (t_On) and Off (t_Off) until the total Exposure Time is reached. This option is used to allow outgasing of thicker negative resists.
Parameter
Exposure Time: Enter the exposure time in seconds
Dose: Enter the exposure dose in mJ/cm²
Constant Dose Channel: Select a sensor
#1: i-line (365 nm)
#2: h-line (405 nm)
Split Exposure: Mark this box to activate the exposure mode Split Exposure
Contact:
Mode:
Proximity allows to define a gap between mask and wafer during exposure (Exposure Gap).
Soft Contact sets the exposure gap to zero, creating a pressure free contact between mask and wafer. After a Soft Contact is created the machine pauses for the Soft Contact Delay Time before continuing with exposure.
In Hard Contact the wafer is brought in direct contact with the mask. A nitrogen purge between substrate and exposure chuck is used to press the substrate against the mask. The N2 pressure is adjustable by a throttle and a pressure regulator. After a Hard Contact is created the machine pauses for the Hard Contact Delay Time before continuing with exposure.
Vacuum Contact creates a vacuum between mask and wafer. This is the strongest contact mode. It is recommended to start the evacuation slowly. Adjust the main vacuum level using a vacuum pressure regulator. The duration of this ramp is set by the Pre Vacuum Pull Time. After that ramp the machine switches to Vacuum Pull Time and releases the wafer from the chuck if Release Wafer has been selected. To release the vacuum chamber after exposure a nitrogen Purge is applied for the duration of the Nitrogen Purge Time.
Parameter:
Depending on the selected Contact Mode different programmable parameters are displayed.
Alignment Gap defines the distance between mask and substrate during alignment.
Exposure Gap defines the distance between mask and substrate during exposure
Soft Contact Delay defines the waiting time before exposure will start.
Hard Contact Delay defines the waiting time before exposure will start
During start of vacuum contact the Pre Vacuum Pull Time defines the ramp to slowly build up the vacuum chamber.
Vacuum Pull Time is the programmed time in seconds for holding the vacuum chamber
For releasing the vacuum chamber a Nitrogen purge is applied for the duration of Nitrogen Purge Time.
Release Wafer
Release Wafer is used during vacuum contact to switch off chuck vacuum in order to strengthen the contact between mask and wafer.
Check Chuck Vacuum
During the program sequence the chuck vacuum is usually monitored. The check mark should be deleted if porous substrates or pieces are used to avoid an error message by the machine. The strength of the chuck vacuum can be adjusted too.
Use Nitrogen Purge
If negative resist is used this option provides an oxygen free surrounding during exposure.
