Abstract: A coherent beam source, e.g., a laser having a cavity that is unstable in at least one direction, is used to produce a coherent beam having an initial intensity profile. The beam is passed through a relay having a Fourier plane containing a spatial filter that serves as a radiation defining mask. The filter has an aperture size and shape effective to modify the beam such that the modified beam forms an image on a substrate. The to image has an intensity profile that more closely approximates a super-Gaussian profile than the initial profile. For example, when the initial intensity profile is Gaussian, the spatial filter may allow passage of only unattenuated the central core of the beam and block completely blocks the wings of the Guassian profile. The modified beam may be more suitable for use in a scanning system used to anneal wafers or other substrates containing integrated circuits.
Abstract: Methods and apparatus for remotely measuring temperature of a specular surface. Method takes two measurements of P-polarized radiation emitted at or near Brewster angle from the surface. First measurement (SA) collects and detects first amount of radiation emitted directly from a surface portion using a collection optical system. Second measurement (SB) includes first amount of radiation and adds quantity of radiation collected at or near at/near Brewster angle and reflected from the surface with a retro optical system with a round-trip transmission t2 that retro-reflects a quantity of radiation received from surface portion back to same surface portion where it reflects and combines with first amount of radiation collected by collection optical system. Measurements SA and SB and t2 are used to determine surface emissivity (?). Calibration curve is used that relates ratio of the first measurement SA to surface emissivity (SA/?), to surface temperature.
Abstract: A method and apparatus for performing laser thermal processing (LTP) using a two-dimensional array of laser diodes to form a line image, which is scanned across a substrate. The apparatus includes a two-dimensional array of laser diodes, the radiation from which is collimated in one plane using a cylindrical lens array, and imaged onto the substrate as a line image using an anomorphic, telecentric optical imaging system. The apparatus also includes a scanning substrate stage for supporting a substrate to be LTP processed. The laser diode radiation beam is incident on the substrate at angles at or near the Brewster's angle for the given substrate material and the wavelength of the radiation beam, which is linearly P-polarized. The use of a two-dimensional laser diode array allows for a polarized radiation beam of relatively high energy density to be delivered to the substrate, thereby allowing for LTP processing with good uniformity, reasonably short dwell times, and thus reasonably high throughput.
Abstract: Methods and apparatuses are provided for positioning a substrate having a target that may be located on either the front-side or the backside of the substrate. The optical detector that views the target contains a signal-generating material that is substantially identical to the substrate material.
Abstract: Provided is an apparatus for substrate processing. The apparatus may include a radiation source emitting a photonic beam, an optical system to form a beam image, a scanning stage, a temperature monitoring means, an output signal generator that compares the monitored temperature with a preset temperature, and a controller coupled to the radiation source and the stage. The stage may be adapted to scan the substrate so the beam image heats a region of the substrate surface, and the temperature monitoring means may collect and analyzes p-polarized radiation of at least three different spectral regions emitted from one or more places on the heated substrate region. The controller in response to a temperature error signal may be programmed to alter the beam intensity and/or to provide changes in the scanning velocity between the stage and the beam. Other apparatuses and temperature monitoring systems are provided as well.
Type:
Grant
Filed:
June 20, 2007
Date of Patent:
June 29, 2010
Assignee:
Ultratech, Inc.
Inventors:
Boris Grek, Michael Weitzel, David A. Markle
Abstract: A chuck for supporting a wafer and maintaining a constant background temperature across the wafer during laser thermal processing (LTP) is disclosed. The chuck includes a heat sink and a thermal mass in the form of a heater module. The heater module is in thermal communication with the heat sink, but is physically separated therefrom by a thermal insulator layer. The thermal insulator maintains a substantially constant power loss at least equal to the maximum power delivered by the laser, less that lost by radiation and convection. A top plate is arranged atop the heater module, supports the wafer to be processed, and provides a contamination barrier. The heater module is coupled to a power supply that is adapted to provide varying amounts of power to the heater module to maintain the heater module at the constant background temperature even when the wafer experiences a spatially and temporally varying heat load from an LTP laser beam.
Type:
Grant
Filed:
December 1, 2004
Date of Patent:
June 8, 2010
Assignee:
Ultratech, Inc.
Inventors:
Iqbal A. Shareef, Igor Landau, David A. Markle, Somit Talwar, Michael O. Thompson, Ivelin A. Angelov, Senquan Zhou
Abstract: Methods for forming a denuded zone in an oxygen-containing semiconductor wafer using rapid laser annealing (RLA) are disclosed. The method includes scanning an intense beam of laser radiation over the surface of the wafer to raise the temperature of each point on the wafer surface to be at or near the wafer's melting temperature for a time period on the order of a millisecond or so. This rapid heating and cooling causes oxygen in the wafer near the wafer surface to diffuse out from the wafer surface. Oxygen in the body of the wafer remains unheated and thus does not diffuse toward the wafer surface. The result is an oxygen-depleted zone—called a “denuded zone”—formed immediately adjacent the wafer surface. The methods further include forming a semiconductor device feature in the denuded zone such as by implanting the wafer with dopants.
Abstract: A method of using beach wattles formed of straw or like material to replenish and renourish a beach area or to create or replace sand dunes removed by storm erosion or the like, the method comprising the steps of placing wattles to entrap sand to build up a replenished mound, then positioning additional wattles on top of the replenished mound to create a higher mound, and repeating these steps as necessary until a mound or dune of desired bulk and height is created. The wattles entrap blowing or deposited sand within the interstices of the fibrous filler material to define an anchor member. The wattles can be placed end-to-end, arranged in patterns, layered or stacked in pyramidal manner.
Abstract: Parallel data bus architecture, lithography system and method for substrate patterning with a high-resolution image by data generation transferring, display or printing high edge placement accuracy images from multiple exposures of plurality of predefined patterns with lower edge placement accuracy. Data bus architecture includes n predetermined patterns in n memory arrays each storing a low resolution pattern to be formed onto microelement array with a data bus connecting memory arrays to an image transducer memory array. Data bus includes switches allowing data transfer from any one memory array to the image transducer array with a memory control unit connected to memory arrays and one or more data bus switches so 2m?1 columns of pattern data stored in the mth memory array are sequentially transferred to 2m?1 memory cell columns of the image transducer memory array, m an integer begging at 1 incremented by 1 to n.
Abstract: Methods and systems for performing laser thermal processing (LTP) of semiconductor devices are disclosed. The method includes forming a dielectric cap atop a temperature-sensitive element, and then forming an absorber layer atop the dielectric layer. A switch layer may optionally be formed atop the absorber layer. The dielectric cap thermally isolates the temperature-sensitive element from the absorber layer. This allows less-temperature-sensitive regions such as unactivated source and drain regions to be heated sufficiently to activate these regions during LTP via melting and recrystallization of the regions, while simultaneously preventing melting of the temperature-sensitive element, such as a poly-gate.
Abstract: An apparatus for measuring the relative positions of frontside and backside alignment marks located on opposite sides of a substrate is disclosed. The apparatus includes upper and lower optical systems that allow for simultaneous imaging of frontside and backside alignment marks. The frontside and backside alignment mark images are processed to determine the relative position of the marks, as a measurement of the alignment and/or overlay performance of the tool that formed the marks on the substrate.
Type:
Grant
Filed:
August 5, 2002
Date of Patent:
May 5, 2009
Assignee:
Ultratech, Inc.
Inventors:
Albert J. Crespin, Jim Woodruff, Ray Ellis, Scott Kulas, Joe Jamello, Emily True
Abstract: A method and apparatus for performing laser thermal processing (LTP) using one or more two-dimensional arrays of laser diodes and corresponding one or more LTP optical systems to form corresponding one or more line images. The line images are scanned across a substrate, e.g., by moving the substrate relative to the one or more line images. The apparatus also includes one or more recycling optical systems arranged to re-image reflected annealing radiation back onto the substrate. The use of one or more recycling optical systems greatly improves the heating efficiency and uniformity during LTP.
Abstract: Methods and apparatuses are provided for improving the intensity profile of a beam image used to process a semiconductor substrate. At least one photonic beam may be generated and manipulated to form an image having an intensity profile with an extended uniform region useful for thermally processing the surface of the substrate. The image may be scanned across the surface to heat at least a portion of the substrate surface to achieve a desired temperature within a predetermined dwell time. Such processing may achieve a high efficiency due to the large proportion of energy contained in the uniform portion of the beam.
Type:
Grant
Filed:
June 28, 2006
Date of Patent:
April 7, 2009
Assignee:
Ultratech, Inc.
Inventors:
Andrew M. Hawryluk, Boris Grek, David A. Markle
Abstract: A method for performing laser thermal annealing (LTA) of a substrate using an annealing radiation beam that is not substantially absorbed in the substrate at room temperature. The method takes advantage of the fact that the absorption of long wavelength radiation (1 micron or greater) in some substrates, such as undoped silicon substrates, is a strong function of temperature. The method includes preheating a portion of the substrate to a critical temperature where the absorption of long-wavelength annealing radiation is substantial, and then irradiating the portion of the substrate with the annealing radiation to generate a temperature capable of annealing the portion of the substrate.
Abstract: Apparatus for and methods of thermally processing undoped or lightly doped semiconductor wafers (30) that typically are not very absorptive of an annealing radiation beam (14) are disclosed. The apparatus (10) uses a relatively low power activating radiation beam (240) with a photon energy greater than the bandgap energy of the semiconductor substrate in order to generate free carriers (315) at and near the substrate surface (32). The free carriers so generated enhance the absorption by the substrate surface of the longer wavelength annealing radiation beam. The annealing radiation beam is thus able to rapidly heat the substrate surface and permit subsequent rapid cooling to obtain, for example, a high level of electrical activity (activation) of dopants (310) formed therein. The invention obviates the need to pre-heat the substrate in order to increase absorption of the annealing radiation beam when performing thermal processing.
Abstract: Provided are methods to be carried out prior to, while, and/or after performing a photolithographic process to a wafer that involve wafer misalignment assessment. The method involves obtaining curvature and/or deformation information of a surface of the wafer over a plurality of locations so as to obtain a curvature map of the wafer. The curvature map is processed to obtain a stress map of the wafer. The stress map is used to determine displacement of a layer of the wafer. The displacement information is used to determine a degree of misalignment in the photolithographic process.
Abstract: Apparatuses and methods are provided for processing a substrate having an upper surface that includes a central region, a peripheral region, and an edge adjacent to the peripheral region. An image having an intensity sufficient to effect thermal processing of the substrate is scanned across the upper surface of the substrate. The image scanning geometry allows processing the central region of the substrate at a substantially uniform temperature without damaging the outer edge. In some instances, the image may be formed from a beam traveling over at least a portion of the central region so that no portion thereof directly illuminates any portion of the edge when the image is scanned across the periphery region. The substrate may be rotated 180° or the beam direction may be switched after part of the scanning operation has been completed.
Abstract: Apparatus and methods for thermally processing a substrate with scanned laser radiation are disclosed. The apparatus includes a continuous radiation source and an optical system that forms an image on a substrate. The image is scanned relative to the substrate surface so that each point in the process region receives a pulse of radiation sufficient to thermally process the region.
Abstract: Techniques and systems for using optical interferometers to obtain full-field optical measurements of surfaces, such as surfaces of flat panels, patterned surfaces of wafers and substrates. Applications of various shearing interferometers for measuring surfaces are described.
Type:
Grant
Filed:
January 28, 2004
Date of Patent:
May 6, 2008
Assignee:
Ultratech, Inc.
Inventors:
Ares J. Rosakis, David Owen, Stephen Gledden, Sean Olson