Ultratech Stepper, Inc.

Ultratech, Inc.

Somit Talwar

David A Markle

Michael O Thompson

Yun Yu Wang

Andrew M Hawryluk

Kurt H Weiner

Karl-Josef Kramer

Gaurav Verma

Iqbal A Shareef

Boris Grek

Ivelin A Angelov

Igor Landau

Guarav Verma

Senquan Zhou

John Edward Cronin

Carol M Gelatos

Cindy Seibel

James B Owens, Jr

Apparatus and 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 heating the substrate to a critical temperature where the absorption of long-wavelength annealing radiation is substantial, and then irradiating the substrate with the annealing radiation to generate a temperature capable of annealing the substrate.

Laser thermal annealing of lightly doped silicon substrates

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.

Laser thermal processing with laser diode radiation

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. Thus, heat from the laser is transferred from the wafer to the heat sink via the heater module and the insulator layer. In the absence of any laser heating, heat is also transferred from the heater module to the wafer as needed to maintain the constant background temperature.

Heated chuck for laser thermal processing

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.

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.

Method of thermal processing a substrate with direct and redirected reflected radiation

Chuck methods and apparatus for supporting a semiconductor substrate and maintaining it at a substantially constant background temperature even when subject to a spatially and temporally varying thermal load. Chuck includes a thermal compensating heater module having a sealed chamber containing heater elements, a wick, and an alkali metal liquid/vapor. The chamber employs heat pipe principles to equalize temperature differences in the module. The spatially varying thermal load is quickly made uniform by thermal conductivity of the heater module. Heatsinking a constant amount of heat from the bottom of the heater module accommodates large temporal variations in the thermal heat load. Constant heat loss is preferably made to be at least as large as the maximum variation in the input heat load, less heat lost through radiation and convection, thus requiring a heat input through electrical heating elements. This allows for temperature control of the chuck, and hence the substrate.

Laser thermal processing chuck with a thermal compensating heater module

Laser scanning apparatus and methods for thermal processing

An apparatus and method for uniformizing the temperature distribution across a semiconductor wafer during radiation annealing of process regions formed in the wafer is disclosed. The method includes forming a silicon layer atop the upper surface of the wafer and irradiating the layer with one or more pulses of radiation having wavelengths that are substantially absorbed by the silicon layer. The silicon layer acts to uniformly absorb the one or more radiation pulses and then transfers the heat from the absorbed radiation to the process regions across the wafer.

Silicon layer for uniformizing temperature during photo-annealing

A method of this invention includes annealing at least one region of a substrate with a short pulse of particles. The particles can be electrons, protons, alpha particles, other atomic or molecular ions or neutral atoms and molecules. The substrate can be composed of a semiconductor material, for example. The particles can include dopant atoms such as p-type dopant atoms such as boron (B), aluminum (Al), gallium (Ga), or indium (In), and n-type dopant atomic species including arsenic (As), phosphorus (P), or antimony (Sb). The particles can also include silicon (Si) or germanium (Ge) atoms or ionized gas atoms including those of hydrogen (He), oxygen (O), nitrogen (N), neon (Ne), argon (Ar), or krypton (Kr). The particles can be used to anneal dopant atoms previously implanted into the substrate. Alternatively, the particle species can be chosen to include the desired implant dopant, the energy of the particle may be chosen to achieve the desired implant depth, and the energy, dose and pulse duration may be chosen to anneal the implanted region during the pulse. This embodiment of the method performs implantation and activation in a single step. If no change in the electrical state of the substrate is required, the particles can include silicon (Si), and germanium (Ge) atoms.

Methods for annealing a substrate and article produced by such methods

A method of forming a doped polycrystalline silicon gate in a Metal Oxide Semiconductor (MOS) device. The method includes forming first an insulation layer on a top surface of a crystalline silicon substrate. Next, an amorphous silicon layer is formed on top of and in contact with the insulation layer and then a dopant is introduced in a top surface layer of the amorphous silicon layer. The top surface of the amorphous silicon layer is irradiated with a laser beam and the heat of the radiation causes the top surface layer to melt and initiates explosive recrystallization (XRC) of the amorphous silicon layer. The XRC process transforms the amorphous silicon layer into a polycrystalline silicon gate and distributes the dopant homogeneously throughout the polycrystalline gate.

Method for semiconductor gate doping

A process for activating a doped region ( ) or amorphized doped region ( ) in a semiconductor substrate ( ). The process includes the steps of doping a region of the semiconductor substrate, wherein the region is crystalline or previously amorphized. The next step is forming a conformal layer ( ) atop the upper surface ( ) of the substrate. The next step is performing at least one of front-side and backside irradiation of the substrate to activate the doped region. The activation may be achieved by heating the doped region to just below the melting point of the doped region, or by melting the doped region but not the crystalline substrate. An alternative process includes the additional step of forming the doped region (amorphized or unamorphized) within or adjacent a deep dopant region ( ) and providing sufficient heat to the deep dopant region through at least one of front-side and backside irradiation so that the doped region is activated through explosive recrystallization.

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Los Gatos, CA, United States of America

Somit Talwar