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

An annealed wafer having enhanced gettering effects for Cu is produced by heating a silicon substrate containing a nitrogen concentration of 5X1014 to 1X1016 / cm3, a carbon concentration of 1X1015 to 5X1016 / cm3, and an oxygen concentration of 6X1017 to 11X1017 / cm3 at a temperature of 650 to 800 DEG C. for a time >=4 hours, and subjecting the heated substrate to argon annealing at a temperature of 1100 to 1250 DEG C., wherein internal stacking fault density after annealing is >=5X108 / cm3.

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 solar cell and a diffusion method of the solar cell. The method comprises the steps that silicon wafers are placed in a diffusion furnace; the temperature in the diffusion furnace is increased to 750-800 DEG C, including terminal values; a source is fed to the diffusion furnace for phosphorus diffusion; the basic quantity of phosphorus being diffused to the silicon wafers is maximum solid solubility of the phosphorus in the silicon wafers at the current temperature in the diffusion furnace; the temperature in the diffusion furnace is increased to 810-820 DEG C, including the terminal values; the phosphorus is diffused to the interiors of the silicon wafers; the temperature in the diffusion furnace is increased to 840-850 DEG C, including the terminal values; the source is fed in the heating process for temperature changing diffusion; the increased temperature is kept; oxygen is fed for high temperature advancing till the diffusive quantity of the phosphorus in the silicon wafers reaches a target value; and after the interior of the diffusion furnace is cooled, the diffusion furnace is opened and the silicon wafers are taken out. According to a cell plate produced by the method, the concentration of a phosphorus impurity on the surface is low; the thickness of a dead layer is small; the distribution gradient of phosphorus concentration is large; and the conversion efficiency is improved.

Provided is a method of producing a semiconductor epitaxial wafer having enhanced gettering ability. The method of producing a semiconductor epitaxial wafer includes: a first step of irradiating a surface of a semiconductor wafer with cluster ions to form a modified layer that is located in a surface portion of the semiconductor wafer and that includes a constituent element of the cluster ions in solid solution; and a second step of forming an epitaxial layer on the modified layer of the semiconductor wafer. The first step is performed in a state in which a temperature of the semiconductor wafer is maintained at lower than 25° C.

The invention discloses a method for preparing a crystalline silicon solar cell. The method comprises the following steps of: forming suede on the front surface of a silicon wafer; performing P ion implantation on the front surface of the silicon wafer; performing heavy doping on the back surface of the silicon wafer, and annealing the silicon wafer; removing a P diffusion layer and phosphorosilicate glass from a heavy doping region; forming an anti-reflection film on the front surface of the silicon wafer; forming a back electrode and an aluminum back field on the back surface of the silicon wafer; and forming a front electrode on the front surface of the silicon wafer. The solar cell prepared by using the method has an efficient p-n junction which is obtained by ion implantation, and has a good back gettering effect; and photoelectric conversion efficiency is remarkably improved.

The object is to provide a method of manufacturing a semiconductor epitaxial wafer having a higher gettering capability and a reduced haze level of the surface of the epitaxial layer. The method for manufacturing a semiconductor epitaxial wafer according to the present invention is characterized in that it includes a first step of irradiating the semiconductor wafer 10 with cluster ions 16 to form a modified layer made of constituent elements of the cluster ions 16 on the surface 10A of the semiconductor wafer. 18. In the second step, after the first step, the semiconductor wafer 10 is subjected to heat treatment for crystallinity recovery in such a manner that the haze level of the semiconductor wafer surface 10A becomes 0.20 ppm or less; and in the third step, in the second step, After the process, an epitaxial layer 20 is formed on the modified layer 18 of the semiconductor wafer.