38results about How to "High gettering capacity" patented technology

The invention relates to an impurity filtering and absorbing flow divider for a tundish. The impurity filtering and absorbing flow divider comprises a tundish body, a permanent layer, an operating layer, a tundish water port, an impurity baffle wall, a turbulence controller and a flow division filter. The impurity filtering and absorbing flow divider is characterized in that the flow division filter is arranged below the impurity baffle wall and comprises a flow division filter body and a plurality of 'V' or 'U'-shaped filter parts, the filter parts are embedded in the flow division filter body and provided with a plurality of through holes, and an adsorption layer is composited on the inner walls of the 'V' or 'U'-shaped filter parts. The impurity filtering and absorbing flow divider has the advantages that specific surface area of the unit size of the flow divider contacting with molten steel is increased to the greatest extent, and collision rate of the impurities and the flow divider is increased. In addition, flow state of the molten steel in the tundish is greatly improved, and the impurities in the molten steel can be further removed.

The present invention discloses a phosphorus diffusion method of a crystalline silicon solar cell. The method comprises the steps of (1) entering into a boat, (2) adjusting temperature to be below 800 DEG C, introducing nitrogen carrying phosphorus source and dry oxygen, and forming a silicon dioxide layer containing phosphorus, (3) carrying out low temperature diffusion, (4) raising the temperature in a furnace and pushing with the rise of the temperature, (5) carrying out first time of high temperature diffusion, (6) raising the temperature in the furnace and pushing with the rise of the temperature, (7) carrying out second time of high temperature diffusion, (8) reducing the temperature in the furnace and pushing with the decrease of the temperature, and (9) reducing the temperature and going out of the boat, and completing a diffusion process. According to the method, an oxidation gettering effect is enhanced and the concentration gradient of the phosphorus doping is controlled, the separation and collection of carriers are facilitated, the open circuit voltage is raised, the temperature difference in a cooling process is controlled, and a crystal boundary gettering effect is enhanced.

The invention discloses a diffusion method used for a crystalline silicon solar battery. The method comprises the following steps of: (1) placing a silicon wafer into a diffusion furnace; rising the temperature from 780-810 DEG C to 840-860 DEG C; and simultaneously introducing POCL3+O2+N2 for 12 to 14 minutes; (2) simultaneously introducing O2+N2 when rising the temperature in the diffusion furnace to 840-860 DEG C and keeping the constant temperature for 2 to 5 minutes; simultaneously introducing the POCL3+O2+N2 for 8 to 12 minutes when rising the temperature from 840-860 DEG C to 870-890 DEG C; reducing the temperature from 870-890 DEG C to 800 DEG C; introducing the O2+N2 in the process of reducing the temperature; stabilizing for 2 minutes at the temperature of 800 DEG C; and introducing the POCL3+O2+N2; and (3) taking the silicon wafer out of the diffusion furnace. In the method, both the requirements on the doping concentration of an emitting region and the surface concentration of the emitting region in diffusion can be met at the same time; a gettering effect is good; and the distribution of a doping curve is more reasonable.

The invention provides a wiring structure forming method which comprises the following steps of: providing a semiconductor substrate, and forming a first medium layer thereon; forming a contact hole on the first medium layer; depositing a first metal layer, covering the bottom and side wall of the contact hole and covering the upper surface of the first medium layer; etching the first metal layer with a wet method, and etching with a dry method to form a bowl-mouth first opening; depositing a second medium layer, covering the bottom and side wall of the first opening and covering the upper surface of the first metal layer; etching the second medium layer to form an inverted trapezoidal through hole; depositing a second metal layer, covering the bottom and side wall of the through hole and covering the upper surface of the second medium layer; and etching the second metal layer with a wet method, and etching with a dry method to form a bowl-mouth second opening. Through the invention, the requirement on planarization of a process platform of near or below 1.5 microns is met without adopting SOG planarization, glue back-etching SOG planarization and the like.

The invention is applicable to the technical field of solar cells, and provides a solar cell and a back contact structure thereof, a cell assembly and a photovoltaic system, the back contact structure comprises first doped regions which are arranged on the back of a silicon substrate at intervals and have polarities opposite to the polarity of the silicon substrate, and second doped regions which have the same polarities as the polarity of the silicon substrate. Protection regions are arranged on the first doped regions; each of the first doped region and the second doped region comprises a first doped layer, a passivation layer and a second doped layer; each protection region comprises an insulating layer and a third doped layer with the same polarity as the second doped region; isolation regions are arranged between the first doped regions and the second doped regions; the protection regions are provided with openings, so that a first conductive layer is connected with the first doped region; and the heights of the first doped regions and the second doped regions are both higher than the heights of the isolation regions. According to the back contact structure provided by the invention, the problem of scratches caused by belt transmission in the existing battery preparation process is solved.

The present invention provides a production method for a semiconductor epitaxial wafer in which increased gettering properties enable metal contamination to be suppressed. In the present invention, the production method for the semiconductor epitaxial wafer is characterized in that the method includes: a first step, in which cluster ions (16) are irradiated on a surface (10A) of a semiconductor wafer (10) so as to form, on the surface (10A) of the semiconductor wafer, a modification layer (18) that is a solid solution of carbon and a dopant element, which are constituent elements of the cluster ions (16); and a second step in which an epitaxial layer (20), which has a lower dopant element concentration than the peak dopant element concentration in the modification layer (18), is formed upon the modification layer (18) of the semiconductor.

The invention provides a low-pressure diffusion and low-temperature oxidation gettering process, and belongs to the field of solar cell gettering processes. The method comprises the steps: low-temperature normal-pressure boat entry, rapid low-pressure heating, high-temperature normal-pressure stabilization, high-temperature low-pressure oxidation, four-step high-temperature low-pressure source communication and knot pushing, long-time cooling, oxidation and impurity absorption, rapid normal-pressure cooling and low-temperature deposition, and low-temperature boat exit. The furnace tube is rapidly cooled for a long time through the steps of cooling, oxidizing and gettering for a long time and controlling the oxygen flow, so that the uniformity and repeatability of diffusion sheet resistanceare improved, the surface doping concentration and junction depth are optimized, the internal defects of a silicon wafer are reduced, and the conversion efficiency of the solar cell is improved.

The invention belongs to the field of solar photovoltaic industry and particularly relates to a preparation method of a tunneling oxidation passivation battery. The method is characterized in that a back surface adopts a polished surface structure so that the light utilization rate can be effectively improved, and the process steps are reduced by adopting one-step deposition of polycrystalline silicon phosphorus doping and growth of a thick oxidation mask layer; a whole surface of the coating is removed, the process window is enlarged, the defect of difficulty in removing the winding plating,namely the defect of difficulty in removing the winding plating due to the fact that boron diffusion is performed on a front surface and polycrystalline silicon is doped on a back surface in the conventional common process flow, is avoided, a certain mark is certainly caused even if the winding plating is completely removed, so the appearance yield is influenced. The method is advantaged in that an annealing and boron doping two-in-one mode is introduced into the method, so the process is simplified, the appearance is not poor, the process flow is short, energy consumption is low, the production yield is effectively increased, production quality is effectively improved, and the like.

The present invention aims to ensure the strength of a surface layer and a main body of a silicon wafer, and enhance the in-plane homogeneity of crystal quality. A method for heat treament of silicon wafer includes the steps as follows: firstly, heat treating silicon wafers in an oxidizing atmosphere in a temperature range between 1300 DEG C to 1400 DEG C; secondly, cooling the heat-treated silicon wafers at a speed of 10 DEG C per second to 150 DEG C per second; and thirdly, heat treating the cooled silicon wafers in the oxidizing atmosphere in a temperature range between 800 DEG C to 1250 DEG C for one hour to one hundred hours.

The invention discloses a light attenuation resistant PERC single crystalline silicon solar cell aluminum paste. The aluminum paste is prepared from the following components in parts by weight: 70 to86 parts of aluminum powder, 0.5 to 2.5 parts of an inorganic binder, 10 to 24 parts of an organic binder and 0.1 to 1.5 parts of an inorganic auxiliary agent. The invention also discloses a preparation method of the aluminum paste. The preparation method comprises the following steps: firstly uniformly stirring the organic binder and the inorganic auxiliary agent, then adding the inorganic binderand the aluminum powder in sequence to be stirred uniformly, and finally grinding to obtain the aluminum paste. An PERC single crystalline silicon solar cell obtained by using the aluminum paste hasthe characteristics of high photovoltaic conversion efficiency and light attenuation resistance.

The invention discloses a method for improving diffusion quality by changing polycrystalline silicon slice phosphorus source components, and relates to the technical field of methods for manufacturing semiconductor devices. The method includes the following steps that (1) phosphorus trichloride is added in phosphorus oxychloride and used as a phosphorus source; (2) oxidization: polycrystalline silicon slices with the manufactured suede are placed in a diffusion furnace, and oxygen is added in the diffusion furnace; (3) deposition: mixed gas of the phosphorus source and the oxygen is added in the diffusion furnace; (4) diffusion: the diffusion furnace is kept at a certain temperature, and then deposited phosphorus silicon slices are diffused in the diffusion furnace. Through the method, the service life of minority carriers in the polycrystalline silicon slices is prolonged, the diffusion gettering effect is beneficially improved, damage to crystal lattices in the high temperature process is reduced, and then photoelectric conversion efficiency is improved.

The present invention provides a method for manufacturing a semiconductor epitaxial wafer having higher gettering capability. This method for manufacturing a semiconductor epitaxial wafer 100 is characterized by having: a first step in which the surface 10A of a semiconductor wafer 10 is irradiated with cluster ions 12 including carbon, oxygen, and nitrogen as constituent elements, and a modification layer 14 is formed on the surface part of the semiconductor wafer 10, the modification layer 14 being such that the constituent elements of the cluster ions are in solid solution; and a second step in which an epitaxial layer 16 is formed on the modification layer 14 of the semiconductor wafer 10.

Provided is a method for manufacturing a semiconductor epitaxial wafer, which can have a higher gettering capability even if the conditions for cluster ion implantation are the same. A method for manufacturing a semiconductor epitaxial wafer according to the present invention includes: a first step of implanting multi-element cluster ions containing 3 elements of carbon, hydrogen, and oxygen as constituent elements into a surface of a semiconductor wafer to form a modified layer in which the constituent elements of the multi-element cluster ions are dissolved in a surface layer portion of thesemiconductor wafer; a second step of performing a defect formation heat treatment for increasing a defect density of the black-dot defects formed in the modified layer after the first step; and a third step of forming an epitaxial layer on the modified layer of the semiconductor wafer after the second step.

The invention relates to a two-step diffusion pretreatment method for casting single-crystal or polycrystal silicon wafers, which comprises the following steps of A, pickling, B, depositing PSG at high temperature, C, primary impurity removal, D, depositing PSG at low temperature, and E, secondary impurity removal. The invention aims to provide a two-step diffusion pretreatment method for casting single-crystal or polycrystalline silicon wafers, which is suitable for effective passivation of the cast single-crystal or polycrystalline silicon wafer, and can reduce defect density in and on the surface of the silicon wafer, reduce recombination of current carriers, improve passivation level and transmission level of the current carriers, therefore, solar cell production can be carried out on the cast single-crystal or polycrystal silicon wafer according to the existing high-efficiency cell piece manufacturing process, and high cell conversion efficiency is obtained.