Abstract: A high-quality isotropic polycrystalline silicon (poly-Si) and a method for fabricating high quality isotropic poly-Si film are provided. The method includes forming a film of amorphous silicon (a-Si) and using a MISPC process to form poly-Si film in a first area of the a-Si film. The method then anneals a second area, included in the first area, using a Laser-Induced Lateral Growth (LILaC) process. In some aspects, a 2N-shot laser irradiation process is used as the LILaC process. In some aspects, a directional solidification process is used as the LILaC process. In response to using the MISPC film as a precursor film, the method forms low angle grain boundaries in poly-Si in the second area.

Abstract: A process of lateral crystallization comprises providing a silicon film on a substrate surface, exposing a localized substrate region at the substrate surface to a laser heating source, and annealing a portion of the silicon film in thermal contact with the localized substrate region by exposing the silicon film to a low-fluence optical annealing source.

Abstract: A substrate and a method for fabricating variable quality substrate materials are provided. The method comprises: selecting a first mask having a first mask pattern; projecting a laser beam through the first mask to anneal a first area of semiconductor substrate; creating a first condition in the first area of the semiconductor film; selecting a second mask having a second mask pattern; projecting the laser beam through the second mask to anneal a second area of the semiconductor film; and, creating a second condition in the second area of the semiconductor film, different than the first condition. More specifically, when the substrate material is silicon, the first and second conditions concern the creation of crystalline material with a quantitative measure of lattice mismatch between adjacent crystal domains. For example, the lattice mismatch between adjacent crystal domains can be measured as a number of high-angle grain boundaries per area.

Abstract: A process of lateral crystallization is provided for increasing the lateral growth length (LGL). A localized region of the substrate is heated for a short period of time. While the localized region of the substrate is still heated, a silicon film overlying the substrate is irradiated to anneal the silicon film to crystallize a portion of the silicon film in thermal contact with the heated substrate region. A CO2 laser may be used as a heat source to heat the substrate, while a UV laser or a visible spectrum laser is used to irradiate and crystallize the film.

Abstract: A process of lateral crystallization comprises providing a silicon film on a substrate surface, exposing a localized substrate region at the substrate surface to a laser heating source, and annealing a portion of the silicon film in thermal contact with the localized substrate region by exposing the silicon film to a low-fluence optical annealing source.

Abstract: A high-quality isotropic polycrystalline silicon (poly-Si) and a method for fabricating high quality isotropic poly-Si film are provided. The method includes forming a film of amorphous silicon (a-Si) and using a MISPC process to form poly-Si film in a first area of the a-Si film. The method then anneals a second area, included in the first area, using a Laser-Induced Lateral Growth (LILaC) process. In some aspects, a 2N-shot laser irradiation process is used as the LILaC process. In some aspects, a directional solidification process is used as the LILaC process. In response to using the MISPC film as a precursor film, the method forms low angle grain boundaries in poly-Si in the second area.

Abstract: Systems and methods for reducing a surface roughness of a polycrystalline or single crystal thin film produced by the sequential lateral solidification process are disclosed.

Abstract: A laser annealing mask is provided with cross-hatched sub-resolution aperture patterns. The mask comprises a first section with aperture patterns for transmitting approximately 100% of incident light, and at least one section with cross-hatched sub-resolution aperture patterns for diffracting incident light. In one aspect, a second mask section with cross-hatched sub-resolution aperture patterns has an area adjacent a vertical edge and a third mask section with cross-hatched sub-resolution aperture patterns adjacent the opposite vertical edge, with the first mask section being located between the second and third mask sections. The section with cross-hatched sub-resolution aperture patterns transmits approximately 40% to 70%, and preferably 50% to 60% of incident light energy density. In some aspects, the section with cross-hatched sub-resolution aperture patterns includes a plurality of different cross-hatched aperture patterns.

Abstract: A wide-slit lateral growth projection mask, projection system, and corresponding crystallization process are provided. The mask includes an opaque region with at least one a transparent slit in the opaque region. The slit has a width in the range of 10X to 50X micrometers, with respect to a X:1 demagnification system, and a triangular-shaped slit end. The triangular-shaped slit end has a triangle height and an aspect ratio in the range of 0.5 to 5. The aspect ratio is defined as triangle height/slit width. In some aspects, the triangular-shaped slit end includes one or more opaque blocking features. In another aspect, the triangular-shaped slit end has stepped-shaped sides. The overall effect of the mask is to promote uniformly oriented grain boundaries, even in the film areas annealed under the slit ends.

Abstract: Systems and methods for reducing a surface roughness of a polycrystalline or single crystal thin film produced by the sequential lateral solidification process are disclosed.

Abstract: Accordingly, a method of suppressing energy spikes is provided comprising projecting a laser beam through a mask having a slit pattern comprising a corner region with edges, and a blocking feature with the corner region to reduce energy spikes projected on a substrate. An alternative method is provided, wherein the corner region is modified such that it is replaced by a more tapered shaped region, preferably a triangle. Also provided, are a variety of mask designs incorporating both corner regions, with and without one or more blocking features, and triangular regions, with or without one or more blocking features. The mask designs provide examples of mask modifications that may be used to reduce energy spikes.

Abstract: Accordingly, a method of suppressing energy spikes is provided comprising projecting a laser beam through a mask having a slit pattern comprising a corner region with edges, and a blocking feature with the corner region to reduce energy spikes projected on a substrate. An alternative method is provided, wherein the corner region is modified such that it is replaced by a more tapered shaped region, preferably a triangle. Also provided, are a variety of mask designs incorporating both corner regions, with and without one or more blocking features, and triangular regions, with or without one or more blocking features. The mask designs provide examples of mask modifications that may be used to reduce energy spikes.

Abstract: A system and method are provided for reducing film surface protrusions in the fabrication of LILAC films. The method comprises: forming an amorphous film with a first thickness; annealing the film using a LILAC process, with beamlets having a width in the range of 3 to 10 microns; in response to annealing, forming protrusions on the film surface; optionally oxidizing the film surface; thinning the film; and, in response to thinning the film, smoothing the film surface. Typically, the film surface is smoothed to a surface flatness of 300 Å, or less. In some aspects of the method, oxidizing the film surface includes oxidizing the film surface to a depth. Then, thinning the film includes thinning the film to a third thickness equal to the first thickness minus the depth.

Abstract: A substrate and a method for fabricating variable quality substrate materials are provided. The method comprises: selecting a first mask having a first mask pattern; projecting a laser beam through the first mask to anneal a first area of semiconductor substrate; creating a first condition in the first area of the semiconductor film; selecting a second mask having a second mask pattern; projecting the laser beam through the second mask to anneal a second area of the semiconductor film; and, creating a second condition in the second area of the semiconductor film, different than the first condition. More specifically, when the substrate material is silicon, the first and second conditions concern the creation of crystalline material with a quantitative measure of lattice mismatch between adjacent crystal domains. For example, the lattice mismatch between adjacent crystal domains can be measured as a number of high-angle grain boundaries per area.

Abstract: A system and method are provided for laser irradiating a semiconductor substrate using a multi-pattern mask. The method comprises: exposing a semiconductor substrate to laser light projected through a multi-pattern mask; advancing the mask and substrate in a first direction to sequentially expose adjacent areas of the substrate to each of the mask patterns in a first predetermined order; and, advancing the mask and substrate in a second direction, opposite the first direction, to sequentially expose adjacent areas of the substrate to each of the mask patterns in the first order. In one aspect, the method further comprises: forming a multi-pattern mask having a first plurality patterns aligned in the first order with respect to the first direction and a second plurality of patterns, corresponding to the first plurality of patterns, aligned in the first order with respect to the second direction.

Abstract: A system and method are provided for reducing film surface protrusions in the fabrication of LILAC films. The method comprises: forming an amorphous film with a first thickness; annealing the film using a LILAC process, with beamlets having a width in the range of 3 to 10 microns; in response to annealing, forming protrusions on the film surface; optionally oxidizing the film surface; thinning the film; and, in response to thinning the film, smoothing the film surface. Typically, the film surface is smoothed to a surface flatness of 300 Å, or less. In some aspects of the method, oxidizing the film surface includes oxidizing the film surface to a depth. Then, thinning the film includes thinning the film to a third thickness equal to the first thickness minus the depth.

Abstract: A substrate and a method for fabricating variable quality substrate materials are provided. The method comprises: selecting a first mask having a first mask pattern; projecting a laser beam through the first mask to anneal a first area of semiconductor substrate; creating a first condition in the first area of the semiconductor film; selecting a second mask having a second mask pattern; projecting the laser beam through the second mask to anneal a second area of the semiconductor film; and, creating a second condition in the second area of the semiconductor film, different than the first condition. More specifically, when the substrate material is silicon, the first and second conditions concern the creation of crystalline material with a quantitative measure of lattice mismatch between adjacent crystal domains.

Abstract: A mask with sub-resolution aperture features and a method for smoothing an annealed surface using a sub-resolution mask pattern are provided. The method comprises: supplying a laser beam having a first wavelength; supplying a mask with a first mask section having apertures with a first dimension and a second mask section with apertures having a second dimension, less than the first dimension; applying a laser beam having a first energy density to a substrate region; melting a substrate region in response to the first energy density; crystallizing the substrate region; applying a diffracted laser beam to the substrate region; and, in response to the diffracted laser beam, smoothing the substrate region surface. In some aspects of the method, applying a diffracted laser beam to the substrate area includes applying a diffracted laser beam having a second energy density, less than the first energy density, to the substrate region.

Abstract: System and methods for processing an amorphous silicon thin film sample into a single or polycrystalline silicon thin film are disclosed.

Abstract: Accordingly, a method of suppressing energy spikes is provided comprising projecting a laser beam through a mask having a slit pattern comprising a corner region with edges, and a blocking feature with the corner region to reduce energy spikes projected on a substrate. An alternative method is provided, wherein the corner region is modified such that it is replaced by a more tapered shaped region, preferably a triangle. Also provided, are a variety of mask designs incorporating both corner regions, with and without one or more blocking features, and triangular regions, with or without one or more blocking features. The mask designs provide examples of mask modifications that may be used to reduce energy spikes.