Week 1 - "Introduction to the Nanofabrication Facility"
Dr. Lendinez discusses the basics of cleanrooms and reviews the fleet of tools at the NFF
Week 2 - "Ellipsometry"
Students collected Ellipsometry data using the Woollam RC2 from silicon substrates coated with SiO2 followed by resistivity measurements
image 1- Sample Placement
image 2- Alignment
image 3- Scanning
image 4 - Data Collection
Week 4 - "Device Fabrication"
Students began the first steps to device fabrication. Markers were etched on to silicon wafers to ensure samples are properly aligned throughout the entire process. This hands on practical provided students the opportunity to actively apply the steps discussed from the third week's lecture while gaining knowledge of machinery aiding in the fabrication process.
Step 1- RCA + Ultrasonic Cleaning
Step 2 - Mask Patterning Alignment Marks
Step 3 - Spincoating Photoresist
Step 4 - Soft Bake
Step 5 - Resist Development
Step 6 - Microscopic Inspection
Step 7 - DRIE (Thermal Oxide Etch)
Step 8 - Etch Depth Profiler Scan
Week 5 - " Dopant Layer Preparation"
This week students patterned openings through the SiO2 in order to apply the dopant layer for next weeks' session. An oxygen plasma source was used to remove excess organic residue from substrates followed by S1813 resist coating. Next, students checked the alignment with previous markers etched in their wafers and exposed using the Quantum ML3Pro then development. Lastly microscopic inspection verified patterns were properly exposed and fully developed resulting in sharp edges and the presence of resistor meanders.
image 1 - Oxygen Plasma
image 2 - Resist Coating
image 3 - Alignment & UV Exposure
image 4 - Development
image 5 - Microscopic Inspection
Week 6 - "Spin on Dopant"
This week students etched through the holes patterned during last week's session then doped the silicon wafers in the opened areas. Silicon Oxide was etched using RIE, resist removal with acetone, followed by RCA cleaning then a soft bake to dehydrate the sample. Wafers were then spin coated with a Spin-On-Dopant (SOD) and cured. The organic layer of the dopant was removed by O2 Plasma then lastly diffused into the silicon by Rapid Thermal Annealing.
image 1 - Dopant Layer Prep
image 2 - Rapid Thermal Annealing
image 3 - Annealing Data
image 4 - SOD Removal
image 5 - Class Discussions
Week 7 - "Glass Layer Etching"
Students began the etch process to remove the glass layer from their samples with Hydrofluoric Acid followed by microscopic inspection. Samples were viewed to ensure glass was removed and prepped for the next layer.
image 1 - HF Etching
.image 2 - Post HF Cleaning
image 3 - Class Observation
image 4 - Microscopic Inspection