Abstract: The present invention relates to gallium (Ga) electroplating methods and chemistries to deposit uniform, defect free and smooth Ga films with high plating efficiency and repeatability. Such layers may be used in fabrication of electronic devices such as thin film solar cells. In one embodiment, the present invention provides a solution for application on a conductor that includes a Ga salt, a complexing agent, a solvent, and a Ga-film having submicron thickness is facilitated upon electrodeposition of the solution on the conductor. The solution may further include one or both of a Cu salt and an In salt.

Abstract: A method and a system are provided for forming planar absorber layers or structures by planarizing and reacting precursor layers in a reactor. A precursor structure is first formed over the front surface of a foil substrate and then planarized through application of pressure by a smooth surface while heated to a first temperature range to obtain a planar layer. The planar layer may be only partially reacted. The planar layer is further reacted at a second temperature range to form a fully or completely reacted planar absorber layer. The planar absorber layer may include at least one Group IB material, at least one Group IIIA material and at least one Group VIA material. The planar absorber layer may be a Group IBIIIAVIA compound layer.

Abstract: An apparatus and method of making moisture resistant solar cells, strings and modules is provided. The method includes reducing the roughness of the finger patterns by coating them fully or partially with a surface preparation film. The surface preparation film firmly attaches itself to underlying finger patterns and electrical leads while forming a smooth surface on which a moisture barrier film is subsequently deposited. Process flows to obtain moisture resistive solar cells, solar cell strings are described.

Abstract: An electrode assembly includes a distribution plate having a plurality of grooves that communicate with openings in an overlying polishing pad layer. The grooves include end openings that allow for draining of process solution, both during processing and subsequent cleaning/rinsing of the pad. Drainage occurs continually during processing, cleaning and rinsing, and so is constricted through the end openings relative to the grooves, to prevent wastage. The end openings are sufficiently large, however, to substantially completely drain fluids from the grooves between steps without delaying robotic motions.

Abstract: Processes and apparatus are described that form a solar cell absorber on a surface of a workpiece by reacting a precursor layer disposed on the surface of the workpiece with an absorber constituent vapor in a heating chamber. The absorber constituent material is delivered from an absorber constituent material delivery system in molten form into a container in the heating chamber and vaporized to be used during the reaction.

Abstract: A process and apparatus which form a solar cell absorber on a surface of a workpiece as the workpiece and a carrier are advanced through a rapid thermal processing (RTP) chamber. In one embodiment, the surface of the workpiece includes a precursor layer and an absorber constituent is disposed on the carrier. Initially an absorber constituent vapor can be formed in the RTP chamber by advancing the carrier into the RTP chamber to vaporize the absorber constituent from the carrier. The workpiece with the precursor layer is then moved into the RTP chamber to react the absorber constituent vapor and the precursor layer to form an absorber layer on the workpiece.

Abstract: A deposition method which deposits a CdS buffer layer on a surface of a solar cell from a process solution including all chemical components of the CdS buffer layer material. CdS is deposited in a deposition chamber by heating the surface of the solar cell absorber to cause the transfer of heat from the solar cell absorber layer to at least a portion of the process solution that is in contact with the surface. Used solution is cooled, and replenished in a solution container and redirected into the deposition chamber.

Abstract: The present invention is directed to different methods used in the formation of an ink, as well as being directed to the formation of layers used in the fabrication of a solar cell, particularly the absorber layer. In one embodiment, the invention is directed to formulating an ink comprising Cu-rich particles and solid Ga—In particles, wherein the step of formulating is carried out at a temperature such that no liquid phase is present within the solid Ga-In particles. In another embodiment, the specific steps taken during the formulation of the ink are described. In yet another embodiment, the process of using the formulated ink to obtain a precursor layer are described.

Abstract: A multilayer structure to form absorber layers for solar cells. The multilayer structure includes a base comprising a contact layer on a substrate layer, a first layer on the contact layer, and a metallic layer on the first layer. The first layer includes an indium-gallium-selenide film and the gallium to indium molar ratio of the indium-gallium-selenide film is in the range of 0 to 0.8. The metallic layer includes gallium and indium without selenium. Additional selenium is deposited onto the metallic layer before annealing the structure for forming an absorber.

Abstract: A process of forming a compound film includes formulating a nano-powder material with a controlled overall composition and including particles of one solid solution The nano-powder material is deposited on a substrate to form a layer on the substrate, and the layer is reacted in at least one suitable atmosphere to form the compound film. The compound film may be used in fabrication of a radiation detector or solar cell.

Abstract: The present invention relates to methods and apparatus for plating a conductive material on a workpiece surface in a highly desirable manner. Using a workpiece-surface-influencing device, such as a mask or sweeper, that preferentially contacts the top surface of the workpiece, relative movement between the workpiece and the workpiece-surface-influencing device is established so that an additive in the electrolyte solution disposed on the workpiece and which is adsorbed onto the top surface is removed or otherwise its amount or concentration changed with respect to the additive on the cavity surface of the workpiece. Plating of the conductive material can place prior to, during and after usage of the workpiece-surface-influencing device, particularly after the workpiece surface influencing device no longer contacts any portion of the top surface of the workpiece, to achieve desirable semiconductor structures.

Abstract: An evaporation tool for forming a dopant structure on a front surface of a continuous workpiece, wherein the front surface includes a precursor layer to form Group IBIIIAVIA absorbers for solar cells and the dopant structure is used to introduce dopants into the precursor layer. The tool includes at least a first vapor source station to deposit a Group VIA material, such as Se, and a second vapor station to deposit a dopant material, such as Na, onto the continuous workpiece. A moving assembly of the tool holds and moves the continuous workpiece within the tool by feeding the continuous workpiece from a first end and taking up from a second end of the tool. A support assembly of the tool contacts a back surface of the continuous workpiece to remove the heat from and apply tension to the continuous workpiece during the process.

Abstract: A thin film solar cell including a Group IBIIIAVIA absorber layer on a defect free base including a stainless steel substrate is provided. The stainless steel substrate of the base is surface treated to reduce the surface roughness such as protrusions that cause shunts. In one embodiment, the surface roughness is reduced by coating surface with a thin silicon dioxide which fills the cavities and recesses around the protrusions and thereby reducing the surface roughness. After the silicon dioxide film is formed, a contact layer is formed over the ruthenium layer and the exposed portions of the substrate to complete the base.

Abstract: The present invention relates to gallium (Ga) electroplating methods and chemistries to deposit uniform, defect free and smooth Ga films with high plating efficiency and repeatability. Such layers may be used in fabrication of electronic devices such as thin film solar cells. In one embodiment, the present invention provides a solution for application on a conductor that includes a Ga salt, a complexing agent, a solvent, and a Ga-film having submicron thickness is facilitated upon electrodeposition of the solution on the conductor. The solution may further include one or both of a Cu salt and an In salt.

Abstract: The present invention provides an apparatus for wet processing of a conductive layer using a degassed process solution such as a degassed electrochemical deposition solution, a degassed electrochemical polishing solution, a degassed deposition solution, and a degassed cleaning solution. The technique includes degassing the process solution before delivering the degassed process solution to a processing unit or degassing the process solution in situ, within the processing unit.

Abstract: A method is provided for forming a Group IBIIIAVIA solar cell absorber layer including indium (In) and gallium (Ga) that are distributed substantially uniformly between the top surface and the bottom surface of the absorber layer. In one embodiment method includes forming a precursor by depositing a metallic layer including copper (Cu), indium (In) and gallium (Ga) on the base, and depositing a film comprising selenium (Se) and tellurium (Te) on the metallic layer. In the precursor, the molar ratio of Te to Ga is equal to or less than 1. In the following step, the precursor is heated to a temperature range of 400-600° C. to form the Group IBIIIAVIA solar cell absorber layer.

Abstract: Substantially uniform deposition of conductive material on a surface of a substrate, which substrate includes a semiconductor wafer, from an electrolyte containing the conductive material can be provided by way of a particular device which includes first and second conductive elements. The first conductive element can have multiple electrical contacts, of identical or different configurations, or may be in the form of a conductive pad, and can contact or otherwise electrically interconnect with the substrate surface over substantially all of the substrate surface. Upon application of a potential between the first and second conductive elements while the electrolyte makes physical contact with the substrate surface and the second conductive element, the conductive material is deposited on the substrate surface. It is possible to reverse the polarity of the voltage applied between the anode and the cathode so that electro-etching of deposited conductive material can be performed.

Abstract: A method and system to modify a surface composition of thin film Group IBIIIA VIA solar cell absorbers having non-uniformly distributed Group IIIA materials or graded materials, such as Indium (In), gallium (Ga) and aluminum (Al). The graded materials distribution varies between the surface and the bottom of the absorber layer such that a molar ratio of (Ga+Al)/(Ga+Al+In) is the highest at the bottom of the absorber layer and the lowest at the surface of the absorber. Within the bulk of the absorber, the molar ratio gradually changes between the bottom and the surface of the absorber. In one embodiment, the surface composition of a graded absorber layer may be modified by removing a top portion or slice of the absorber layer, where the molar ratio is low so as to expose the inner portions of the absorber layer having a higher molar ratio of graded materials.

Abstract: A method of filling a conductive material in a three dimensional integration structure feature formed on a surface of a wafer is disclosed. The feature is filled with a dispersion containing a plurality of conductive particles and a solvent. Then, the solvent is removed from the feature, leaving the plurality of conductive particles in the feature. These two steps are repeated until the feature is filled up with the conductive particles. Then, the conductive particles are annealed in the feature, thereby forming a dense conductive plug in the feature.

Abstract: A method and apparatus for electropolishing a conductive layer on a wafer is provided. The apparatus includes an electrode and a conductive member having openings permitting an electropolishing solution to flow through it. Surface of the conductive member includes a surface profile. During the electropolishing process, the surface of the conductive element is placed across from the conductive layer and a potential difference is applied between the conductive layer and the electrode. The process forms a conductive layer profile of the conductive layer.