OmniEtch
OmniEtch bare die de-layering system uses etch chemicals that are both adsorbed and absorbed onto the surface of a proprietary Carrier Medium (designation 36-6).
OPERATING PRINCIPAL
Controlled chemical etching for de-layering of IC die has never been possible due to etch chemicals leaking through vias from one metal layer to another, causing cross contamination and etching of successive die layers. Until now it has only been possible to remove surface passivation layers to expose the uppermost metal layer. This metal layer can be removed by manual chemical etching, but invariably chemicals leak and diffuse through the interconnect vias to contaminate lower layers in the die stack.
To overcome this problem the process of backside emission microscopy was developed. Backside emission microscopy itself is a very demanding methodology, due to the difficulties of preparing suitable thinned and polished die, while avoiding mechanical and thermal damage to the samples.
CARRIER MEDIUM (36-6)
OmniEtch overcomes the problems associated with front side die de-layering by using etch chemicals that are both adsorbed and absorbed onto the surface of an inert, proprietary Carrier Medium (36-6). This material is available exclusively from Nisene Technology and is perhaps best described as a complex quaternary polysaccharide (for more details please see OmniEtch Technical Bulletins 3001, 3002, and 3003).
Any etch chemistry of choice can be adsorbed/absorbed onto the Carrier Medium surface. This Carrier Medium, now charged with the appropriate etchant, is passed across the surface of the die in a Teflon etch chamber designed to allow an exact laminar flow of etchant across the die surface.
The etchants used in de-layering can be re-circulated. The etchant is pumped from the heated reservoir etchant bottle through the Etch Chamber, and then returns to the reservoir bottle.
The OmniEtch is equipped with three supply bottles and one purge bottle housed in a Bottle box compartment that is equipped with double containment and liquid sensors to monitor any possible spilled chemicals.
The system is constructed with all Teflon wetted parts. All mechanical components are manufactured form corrosion resistant polymers.
The pump has variable speed control. The pump head mechanism is separated from the electronic components by a bulkhead that isolates the electrical components from the fluid handling side of the system. The pump and all fluid handling components of the OmniEtch are purge-able with nitrogen gas to ensure complete removal of any residual etchant from both the Etch Chamber and supply lines prior to opening the chamber for sample exchange.
OMNIETCH DESIGN AND OPERATING PARAMETERS
- User selectable Etch Chemistries, Etch Time and Etch Temperature
- Variable Etch Speed
- IC Sample View Port
- Minimal Consumption of Etchants
- Double Containment system for all Etchants
- Simple Sample Loading
- Controlled Etching of Aluminum, Copper, Oxides, and select barrier metals
- Compatible with almost all Acidic and Basic Etch Chemistries
- Sequential Die Layer Removal
- Proprietary Etchant Carrier Medium — Eliminates Etchant Migration through Vias
- No thermal or mechanical sample damage
- CE and SEMI S-2 Certifications in progress
Delivery Schedule: first units available for shipment May 2004
