Industrial applications require high throughput rates, which can only be achieved by fully automated measurements. Optical measuring tools with automatic sample handling especially designed for the semiconductor, MEMS and LED industry, easily configurable for different sample (wafer) types, are optimally suited.
To avoid mechanical contact between the handling unit and the wafer, we offer non-contact end effectors using ultrasound air bearing technology.
Ultrasound air bearing technology offers a number of advantages over conventional solutions. This means that handling on processed and coated wafers can be carried out without damaging the surface and particle deposits can be avoided. Our non-contact end effectors can be retrofitted to any MicroProf® MHU. The ultrasound air bearing creates a supporting air film between its surface and the substrate. This avoids mechanical contact and the wafer floats friction-free on an air cushion. This ensures an even, contact-free lift of the wafer during the transfer process. To prevent sideways movement, 4 side-limiting pins (2 of them moveable) are required. The wafer is only fixed by these pins and not clamped.
The handling unit is equipped with
- a robot arm with two vacuum end effectors,
- loading stations for open cassettes
- including mapper as well as optional OCR reader, pre-aligner, etc.
Throughput rates of up to 220 wafers per hour can be achieved.
A two-arm vacuum gripper automatically places the wafers from up to four cassettes at the measuring position. Thanks to a magnetic holding mechanism, the end effector can be easily changed and adapted to wafers in sizes from 2 to 8 inches (200 mm). Optionally, the MicroProf® MHU can be equipped with a wafer sorting system.
The MicroProf® MHU can be equipped with numerous additional functions. Based on the multi-sensor concept, additional sensors can be retrofitted at a later time. It is also possible to order the MicroProf® MHU without an automatic handling unit and, if required, to extend the tool with this unit.
With its multi-cassette handling, the MicroProf® MHU is the ideal tool for the fully automated measurement of wafers. The instrument inspects wafers with diameters from 2" to 8" fully integrated into the fab workflow. Of course, this tool also offers the option of double-sided sample inspection. This enables simultaneous measurement of the top and bottom sides of the sample and determination of the sample thickness. Thus, the total thickness variation (TTV) of the sample can be determined together with surface parameters, e.g. roughness, waviness and flatness of both sides. A complete wafer inspection with analysis of the global and local wafer parameters is also possible. A function for sorting good and bad samples is available.
Another domain of the MicroProf® MHU is the film thickness determination of thin films or layer stacks. Further applications are for example the measurement of steps, bumps, through-silicon-vias (TSV), trenches, etc.
Due to its fully SEMI-compliant design, nearly maintenance-free hardware components and high throughput, the MicroProf® MHU is the perfect solution for use in production.
Do you have any further questions or comments? Then contact us! Our experts will be happy to help you solve your measuring tasks.
Full wafer map of a Si wafer in 3D view showing bow
thickness of a Si wafer, post grinding
Film thickness, SiO2 layer on a Si wafer
Thickness map of a photoresist coating
Thickness profiles of a photoresist coating along the marked lines
Area measurement of micro pillars
Profile of micro pillars along the blue line