Apparatus for the selective separation of two layers of material using an ultrashort pulse source of electromagnetic radiation

Abstract

A direct-write apparatus and end use device for selective separation of at least one layer of material from another layer of material at the interface between them using a beam of electromagnetic radiation from an ultrashort pulse source is disclosed.

1 . An apparatus for separating at least one layer of material from another layer of material comprising: an ultrashort pulse source of electromagnetic radiation generating a beam consisting of at least one pulse and at least one component selected from a group comprising at least one element to direct the beam to an interface, at least one element chosen to shape the spatial profile of the beam, at least one element to shape the temporal profile of the beam, at least one element to control the polarization of the beam, at least one element to control the beam pointing direction, at least one element to control the fluence of the pulse incident on an interface between at least two layers of material, at least one element to move the beam in any direction with respect to the interface, and at least one controller to control the beam so that at least one layer of material is separated from the other layer of material at the interface in a predetermined pattern. 
     
     
         2 . The apparatus of  claim 1 , wherein the ultrashort pulse source of electromagnetic radiation generates a beam of pulses with pulse width chosen to be in the range of between 10 femtoseconds and 1 picosecond, one picosecond, or between 1 picosecond and 100 picoseconds. 
     
     
         3 . The apparatus of  claim 1  further comprising an ultrashort pulse source of electromagnetic radiation includes a diode pumped or CW lamp pumped solid state source preferably of pulse width ranging from 1 fs to 100 ps, pulse energy 1 nanoJoule to 1 milliJoule and the pulse repetition rate in a range of 1 Hz to 5 gigahertz (GHz.) 
     
     
         4 . The apparatus of  claim 1  wherein the ultrashort pulse source of electromagnetic radiation has a center wavelength of operation chosen to be within the range of 100 nm to 1000 nm, 1000 nm, or 1000 nm to 10,000 nm. 
     
     
         5 . The apparatus of  claim 1  wherein the wavelength of the electromagnetic radiation beam from the ultrashort pulse source of electromagnetic radiation preferably has a fundamental frequency of operation between 700 nm-1200 nm wavelength or a second harmonic of the fundamental frequency or a third harmonic of the fundamental frequency: wherein the ultrashort pulse source preferably has at least one of the following, a beam divergence of less than 100 milliradians, a beam pointing stability of less than 100 microradians/degree C., an amplitude stability less than 1% rms, noise less than 1% rms or a near Gaussian spatial mode with a times diffraction limit parameter of less than 2. 
     
     
         6 . The apparatus of  claim 1  wherein the pulsed beam of electromagnetic radiation from the ultrashort pulse source is moved in a repetitive pattern to minimize the cumulative effect of heating and reduce the embrittlement of one or more materials, or one or more structures adjacent to zone where separation is to occur. 
     
     
         7 . The apparatus of  claim 1 , wherein the electro-optic modulator or acousto-optic modulator serve as a means of turning on or turning off the pulse of electromagnetic radiation. 
     
     
         8 . The apparatus of  claim 7 , including a photoelectric sensor providing a signal to control the electro-optic modulator or acousto-optic modulator in order to select the number of pulses, the pulse energy, or the average power output incident on the interface. 
     
     
         9 . The apparatus of  claim 1  wherein the spatial separation in at least one dimension is less than the spot size of the beam of electromagnetic radiation at the interface. 
     
     
         10 . An end use device composed at least in part of a multilayer component wherein one layer of material has been separated from at least a portion of another layer of material at the interface between them by directing energy from at least one pulse of electromagnetic radiation of ultrashort duration to at least a portion of the interface sufficient to cause the layers to separate. 
     
     
         11 . The end use device of  claim 10  wherein at least one layer of material is at least partially transparent in the visible. 
     
     
         12 . The end use device of  claim 10  wherein at least one layer of material is electrically conductive. 
     
     
         13 . The end use device of  claim 10  wherein the substrate is transparent in any one or more of the regions comprising the visible and near infrared (IR.) 
     
     
         14 . The end use device of  claim 10  wherein the substrate is an electrical insulator. 
     
     
         15 . The end use device of  claim 10  wherein the at least one component is fabricated by a method comprising controlling one or more of the properties of the incident radiation selected from the group that includes the pulse duration, the wavelength, the spatial intensity profile, the chirp, the temporal characteristics, and the polarization of the pulse incident on the interface so as to improve the efficiency of the separation of the at least two layers without damaging the substrate or any material adjacent to the ablation zone. 
     
     
         16 . The end use device of  claim 10  wherein the component comprises at least two layers of material have an ablation threshold that is higher than the ablation threshold at the interface between them. 
     
     
         17 . The end use device of  claim 10  wherein the component of the multilayer material has had at least one layer of material separated from the substrate in a predetermined pattern without damaging the substrate or any material adjacent to the separation zone. 
     
     
         18 . The end use device of  claim 10  wherein the layer of material to be locally separated is a TCO oxide such as Indium Tin-Oxide (ITO), a mixture of materials such as silver conductive paste, an electrically conductive organic thin film or a layer of a metal. 
     
     
         19 . The end use device of  claim 10  wherein the component has a substrate comprised of one or more of a substance chosen from a group comprising a metal, a semiconductor, a polymer, a ceramic, a glass, a crystalline material or a composite material. 
     
     
         20 . The end use device of  claim 10  wherein the component was at least partially fabricated by causing an evanescent wave of electromagnetic radiation to propagate into the interface. 
     
     
         21 . The end use device of  claim 10  wherein the component comprises the two layers whose ablation threshold is higher than the ablation threshold at the interface. 
     
     
         22 . The end use device of  claim 10  wherein the component is first thinned by ablation using electromagnetic radiation. 
     
     
         23 . The end use device of  claim 10  wherein the component was fabricated by controlling the pulse width of at least one of the pulses of electromagnetic radiation to have a pulse duration of less than 10 picosecond. 
     
     
         24 . The end use device of  claim 10  wherein the component was fabricated by controlling the pulse width of at least one of the pulses of electromagnetic radiation to have a pulse duration of less than 1 picosecond. 
     
     
         25 . The end use device of  claim 10  wherein the component was fabricated by controlling the pulse width of at least one of the pulses of electromagnetic radiation to have a pulse duration of less than 100 femtoseconds. 
     
     
         26 . The end use device of  claim 10  wherein the component comprises a substrate that is at least partially transparent to light with a wavelength between 5 microns to 100 nm. 
     
     
         27 . The end use device of  claim 10  wherein the cumulative heating effects adjacent to the zone of separation component is minimized by repetitive movement of the beam over a localized area. 
     
     
         28 . The end use device of  claim 10  wherein the zone of separation has a feature in at least one dimension that is less than the spot size of the beam of electromagnetic radiation at the interface.