High Frequency Radiation Weapon

The first process to be done: Wafer Cleaning Wafers must be free of contamination at all stages of the antenna fabrication process Wafers are cleaned in a strong acid and rinsed in DI water Safety glasses and chemical gloves are required for this step Once cleaned, wafers are ready for the next process

Engr 1202 ECE Lab Micro Planar Antenna Traveler

Neat, organized work area Correctly labeled containers Safety Glasses Chemical Gloves Neat, organized work area Correctly labeled containers

Pour 100 ml of Hydrogen Peroxide (H2O2) into a crystallizing dish Carefully add 150 ml of Sulfuric Acid (H2SO4) to the Hydrogen Peroxide This solution is exothermic (creates heat) and may start to gently smoke Carefully place one wafer into the solution. The solution will start to bubble, this is due to the release of oxygen as the Hydrogen Peroxide is reduced to H2O. This is a “one time” only use cleaning solution This cleaning mixture removes both organic material and metallic material This cleaning solution is known as “Piranha” clean as the rapid bubbling resembles attacking piranha.

Crystallizing dishes marked for sulfuric acid and hydrogen peroxide are used to clean the wafers

Place wafer into sulfuric acid/hydrogen peroxide cleaning mixture using special wafer tweezers marked with green tape Cleaning solution of 150 ml sulfuric acid into 100 ml of hydrogen peroxide Wafer tweezers Crystallizing dish

After 10 minutes in the sulfuric acid/hydrogen peroxide solution the wafers are loaded into a wafer carrier and put into the cascade DI water rinse for 5 minutes. Wafer Carrier Cascade DI water tank

After the 5 minute DI water rinse, the wafer carrier is submerse in the 10% HF bath for 10 seconds 10% HF - 90% DI water

After the HF dip, return the wafers to the cascade rinse tank and rinse in DI water for 15 minutes or 12 mega-ohm resistivity, which ever comes first.

Nitrogen valve behind wafer dryer must be turned on before using After complete DI water rinsing, the wafer carrier is placed into the wafer dryer to dry the wafers and complete the cleaning process Nitrogen valve behind wafer dryer must be turned on before using Wafer carrier must be carefully loaded into the wafer dryer to avoid breaking wafers Wafer Dryer

Wafer cleaning successfully completed

Homework Assignment Assignment #6 –worksheet from web site Meet as a team Record members in attendance and time of meeting Decide on application, Cellular, Bluetooth/Wi-Fi, RFID Determine frequency band to be used Find wavelength Decide on antenna design length – preliminary choice, can be changed later Find antenna length Submit ONE worksheet per team at next lecture