Tiza Lab, LLC

Vladimir V Makarov

Sergey Macheret

Etch assisting agents for focused ion beam (FIB) etching of copper for circuit editing of integrated circuits both prevent loss of adjacent dielectric due to sputtering by the ion beam, and render sputtered re-deposited copper on adjacent surfaces non-conductive to avoid electrical short circuits. The agents are characterized by having an N&#x2014;N (N being Nitrogen) bonding in their molecules and boiling points between about 70&#xb0; C. and about 220&#xb0; C., and include hydrazine and water solutions, hydrazine derivatives, NitrosAmine derivatives saturated with two hydrocarbon groups selected from Methyl, Ethyl, Propyl and Butyl, NitrosAmine related compounds, and Nitrogen Tetroxide. Preferred agents are Hydrazine monohydrate (HMH), HydroxyEthylHydrazine (HEH), CEH, BocMH, BocMEH, NDMA, NDEA, NMEA, NMPA, NEPA, NDPA, NMBA, NEBA, NPYR, NPIP, NMOR and Carmustine, alone or in combination with Nitrogen Tetroxide. The agents are effective for etching copper in high aspect ratio (deep) holes.

FIB process for selective and clean etching of copper

The present invention provides a method of obtaining a bright source of ions with narrow energy spread for focused ion beam applications using micro plasmas. As a preferred embodiment, a high pressure microplasma source operating in a normal glow discharge regime is used to produce a cold bright focused beam of Xeand/or Xeions having ion temperature of the order of 0.5-1 eV and a current density on the order of 0.1-1 A/cmor higher.

Microplasma ion source for focused ion beam applications

A high pressure microplasma source operating in a normal glow discharge regime is used to produce a cold bright focused beam of Xeand/or Xeions having ion temperature of the order of 0.5-1 eV and a current density on the order of 0.1-1 A/cmor higher for focused ion beam applications.

Silicon, silicon dielectrics and low-k dielectrics are etched in a focused ion beam process using gaseous fluorinating etchants selected from the group of triethylamine trihydrofluoride (TEATHF) and xenon fluoride. Xenon fluoride is combined with a secondary protecting agent to avoid undesired corrosion of bare silicon. The protecting agent may be an oxidizing agent such as oxygen, perfluorotripentylamine (PFTPA), or a heavy completely fluorinated hydrocarbon.

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Fremont, CA, United States of America

Vladimir V Makarov