Introduction to plasma and plasma process
Introduction to Plasma
Plasma is an ionized gas phase substance that consists of ions, electrons and neutral atoms and/or molecules that grossly maintain charge neutrality.
DC Glow Discharge
In DC glow discharge, there is a fixed cathode and a fixed anode. Electrons will be accelerated from cathode to anode and acquire more energy.
Capacitively Coupled Discharge
Capacitively coupled discharge works similarly as DC glow discharge. They both rely on the electric field created by voltage applied on the electrodes to accelerate free-moving electrons to knock out bonded electrons in neutrals.
Inductively Coupled Discharge
Inductively coupled discharge also uses RF power supply like capacitively coupled discharge. Frequency of the power is usually in tens of KHZ to tens of MHz range.
Microwave Plasma
Capacitively coupled discharge and inductively coupled discharge are usually driven by RF power supply with frequency range from tens of KHz to less than 100MHz.
ECR (Electron Cyclotron Resonance) Plasma
ECR excitation method also use microwave to heat up electrons.
What is plasma cleaning
Plasma cleaning is the process of creating energetic plasma to remove nanometer-scale impurities and contaminants from surfaces.
Photoresist Ashing and Stripping
Photoresist ashing or stripping refers to the process of completely removing the photoresist layer on the substrate.
Plasma photoresist Descum
Photoresist descum is the process of removing the photoresist residual in the open trenches or holes after the lithography and developing steps.
Plasma Cleaning Prior to Wire Bonding
Plasma cleaning prior to wire bonding removes organic, oxide and fluoride contaminations on the surface, promotes better interfacial adhesion for wire bond and chip packaging, reduces non-stick-on-pad (NSOP) and bond lifting problems.
Plasma Cleaning for SEM and FIB
Hydrocarbon contamination is a prevalent issue in many high vacuum analytical equipment, such as SEM, FIB, TEM, and XPS systems.