A method is disclosed for mechanically and electrically bonding metallic materials and semiconductor materials. The method according to the invention may be used, for example, in forming a semiconductor electrical heater, particularly for use in electrical smoking articles. A metallic element, such as a copper alloy power supply tab, is laser welded to a semiconductor element, such as a doped silicon resistive heater element. A laser beam is directed through a hole in the copper alloy tab to melt some silicon material, which flows into the hole in the copper tab, reacts and intermixes with the copper and solidifies to form a slug containing copper silicide. A protective material such as nickel may be applied to protect the copper silicide from oxidation if desired. An ohmic, low resistance contact and high strength bond is provided between the parts.

Semiconductor electrical heater and method for making same

A solar cell fabrication procedure which is characterized by (1) removal of the front surface electrode plating mask after preliminary metallization of the front surface electrodes, (2) a passivation step which, inter alia, results in the formation of an altered silicon substrate surface layer, and (3) use of the altered surface layer as a plating mask for subsequent metallization steps involving, for example, immersion plating of nickel and immersion plating of electroplating of copper.

Method of fabricating solar cells

A solar cell and a method for manufacturing the same are disclosed. The solar cell includes a substrate of a first conductive type, an anti-reflection layer that is positioned on the substrate and is formed of a transparent conductive oxide material, a plurality of emitter layers on the substrate, the plurality of emitter layers being of a second conductive type opposite the first conductive type, a plurality of first electrodes on the plurality of emitter layers, and a plurality of second electrodes that are electrically connected to the substrate and are positioned to be spaced apart from the plurality of first electrodes. The first electrodes and the second electrodes are positioned on the same surface of the substrate.

Solar cell and method for manufacturing the same

An electrical contact formed in a groove in the surface of a semiconductor material facilitates an advantageous contact with the material for a given cross-sectional area of contact when compared with a contact of the same cross-sectional area formed on the surface of the material. The grooved contact significantly reduces shading of the surface of the semiconductor material compared with an equivalent surface contact.

Buried contact solar cell

A solar cell fabrication procedure which is characterized by formation of a "polysilazane" coating (10) on a silicon substrate (2), photo-lithography of the polysilazane coating to form a plating mask pattern (12A), a heating step which removes residual photoresist and converts the polysilazane coating to a denser form of silicon nitride (10A) having a reduced etch rate, and use of densified silicon nitride (10A) as a mask for the plating of electrode metal (20) and also as an anti-reflection coating.

Method of fabricating solar cells.

A simple method for plating nickel onto silicon which renders unnecessary any catalyzing pretreatment of the silicon surface which is to receive the nickel. The method comprises the immersion of a silicon substrate in a suitable nickel bath in order that nickel ions in the bath will be reduced to solid nickel and deposited onto the substrate so as to form an adhering layer thereon. The method is especially advantageous in plating nickel onto silicon shallow junction devices for the purpose of providing ohmic contacts.

Nickel plating method

A method for electrolessly plating nickel onto silicon which renders unnecessary any catalyzing pretreatment comprises the immersion of a silicon substrate in a nickel chloride bath containing a fluoride eg ammonium fluoride or hydrogen fluoride The coated product may subsequently be heated in an atmosphere of H2 to form an ohmic contact at the Ni/Si interface Ni is selectively deposited in regions of the substrate not covered with silicon oxides The method is especially advantageous in plating nickel onto silicon shallow junction devices for use as photovoltaic solar cells An intermediate layer of aluminium may be provided as a backing on the rear of a solar cell

Electroless plating of nickel onto silicon

Coating silicon with nickel by electroless-plating

Ni is plated onto an Si body by (a) immersing the body in an aq. bath of NiCl2 and NH4F and/or HF; (b) maintaining in the bath, so Ni ions are converted to solid Ni and deposited on the body as an adherent Ni layer; and (c) withdrawing from the bath. An ohmic Ni content is formed by (d) sintering to produce an Ni silicide at the junction of the layer and body. A photovoltaic solar cell is made by (i) providing a first-type Si body having a second-type top region, and having Si oxide on the top surface with a grid pattern of exposed Si oxide free Si regions; (ii) plating as (a)-(c) in a bath of NiCl2 and ionisable F cpd., (iii) washing with dionised water to remove loose particles; (iv) sintering to form Ni silicide and (v) removing Si oxide from the top surface. Adherent Ni layers are formed without catalysation pre-treatment and use of expensive Pd, and without introducing Ni phosphide contaminants, and ohmic contacts are formed with sintering at low temps. for short times, avoiding junction penetration.

Patel Kirit B

Papers

Nickel plating method

Electroless plating of nickel onto silicon

Coating silicon with nickel by electroless-plating

Electroplating adherent nickel on silicon - in bath of nickel chloride and ionisable fluoride