Common Delayering Methods

Fundamentally, delayering can be defined to be an etching process. Etching is the removal of material from a solid surface which is in contact with the etchant.  The common and established delayering methods include:

Wet Chemical Etch is where liquid reactants are in contact with the IC chip creating a reaction with the surface materials. The reaction products are gas or liquid which diffuse away from the IC layer. The wet etch method can suffer from chemical selectivity shortcomings where reactants do not react with all the IC surface materials in a manner which provides the desired layer, leaving a mixed surface which would require additional steps to remove remnants.

Mechanical Polishing is where the polishing tools are employed to remove surface material. This technique uses the application of force and slurries to physically remove material. This method is susceptible to uneven application of force and makes it difficult to control planarization. The technique is vulnerable to residual contamination and damage from the polishing compounds or slurries, plus layer non-uniformities are a risk which exposes multiple layers and not the desired common layer.

Dry Plasma Etch is where the IC chip is immersed in a gaseous plasma which is a mixture of atoms, neutral radicals, ions and electrons. Through means of electrostatic forces and gas kinetics, the ions and radicals arrive on the IC surface, removing material by either a physical sputter or dry chemical etching mechanism. This dry plasma etch method is a simple and basic material removal technology which suffers because of its inherent physical limitations and rudimentary control capabilities. For example, this method struggles to etch Copper at a meaningful rate even with the incorporation of special tactics such as using very corrosive gases.

Ion Beam Etching technology. The IBE process method advances delayering outcomes, including tight layer planarization, nanometer etch layer precision, universal material removal and removal uniformity across layer when compared to the prevailing methods.

Ion Beam Etching is a dry plasma etch method which utilizes a remote broad ion beam source to remove IC chip material by physical inert gas means and chemical reactive gas means.  From this remote ion source, a directed and neutralized ion beam is accelerated towards the IC chip.  Ion beam etching independently and precisely controls critical material removal properties such as etch rate, etch material selectivity, surface planarization, and material removal uniformity over the entire IC chip surface.  This level of control over the entire IC chip surface is unique to our ion beam etching approach.