32results about How to "Good gettering effect" patented technology

There is disclosed a photovoltaic conversion device constructed using a p-type crystalline silicon substrate 404 doped with boron, which comprises a bulk substrate region 404, regions other than the bulk substrate region including an n-type region 403a joining to a light receiving surface of the bulk surface region, a BSF region 405 joining to a back surface of the bulk surface region,

• [0001]
  • wherein with regions other than the bulk substrate region 404 being removed, when a minority carrier diffusion length of the bulk substrate region 404 is measured from the light receiving surface of the bulk surface region, 0.5<(L1/Lpeak)is satisfied, where L1is a minority carrier diffusion length at an arbitrary measuring area of the light receiving surface of the bulk surface region, and Lpeak is a diffusion length corresponding to a maximum peak on the side of higher diffusion length of a histogram, the histogram being formed from data obtained when a minority carrier diffusion length of the light receiving surface of the bulk surface region is measured at a plurality of measurement areas. This structure can reduce influence of impurities such as Fe, and enhances utilization efficiency of silicon ingots. With this structure, a photovoltaic conversion device with high photovoltaic conversion efficiency can be realized.

The invention relates to an encapsulation structure for wafer backside. The structure comprises a semiconductor substrate and a multilayered structural layer which is arranged at the bottom of the semiconductor substrate and is formed by combining a polysilicon layer and an insulating layer (such as a silicon dioxide layer); the multilayered structure can promote the effect of impurity absorption, effectively prevents automatic doping, improves the phenomenon of burr, and saves process cost; and through the structure, the bowing degree and the warping degree of the silicon substrate are easily adjusted.

The invention discloses a method for removing transition metal impurities in a silicon wafer or silicon device in a sucking mode at the indoor temperature. Low-dose electron irradiation with the dose smaller than 5000 Gy is carried out on the silicon wafer or silicon device at the indoor temperature to enable the transition metal impurities in a to-be-cleaned area of the silicon wafer or an active area of the silicon device to be diffused to a nearby impurity sucking defect area, and therefore the concentration of the transition metal impurities in the to-be-cleaned area of the silicon wafer or the active area of the silicon device is lowered. Compared with an existing silicon material impurity sucking method, the method is implemented at the indoor temperature, and therefore the method can be used for silicon wafer or silicon device impurity sucking, is not limited to the single-crystal or polycrystalline silicon wafer and the silicon device, and is also suitable for other semiconductor materials such as germanium, and corresponding devices.

The invention discloses an aluminum-boron common gettering method for a silicon slice, which comprises the following steps of: preparing a boron-doped aluminum source, cleaning the silicon slice, forming a boron aluminum layer on the surface of the silicon slice by using screen printing or spin coating technology, performing annealing with one or more steps, and removing the surface layer of the silicon slice. The boron is doped into the aluminum by using the characteristic that the boron has high solid solubility in silicon compared with the aluminum, and the boron is doped into a heavy doped layer on the back of the silicon by using an alloying process of the aluminum and the silicon to obtain an aluminum-boron common gettering layer with high doping concentration. The aluminum-boron common gettering method can form a deeper and uniform gettering layer with higher doping concentration at the same annealing temperature, achieve the gettering effect of other processes at a low temperature, and reduce the influence of high temperature on the performance of the silicon slice. The aluminum-boron common gettering method has the characteristics of low cost, easy operation and good gettering effect, and has great application prospect.

A silicon epitaxial wafer of the invention comprises a silicon single crystal wafer sliced from a CZ silicon ingot doped with carbon in a concentration range of not less than 5×10¹⁵ atoms/cm³ and not more than 5×10¹⁷ atoms/cm³ and an epitaxial layer consisting of a silicon single crystal epitaxially grown on a front surface of the silicon single crystal wafer. A polycrystalline silicon layer having a thickness of not less than 0.5 μm and not more than 1.5 μm is formed on a back surface of the silicon single crystal wafer.

The invention discloses a silicon wafer phosphorus diffusion gettering technology for manufacture of a solar cell, which comprises the following steps of: coating a phosphorus source on the surface of a silicon wafer; heating the silicon wafer to 800-1,100 DEG C at the rate of 50-200 DEG C/s in the presence of a protective gas atmosphere; preserving the temperature for 1-10 minutes; then cooling to 500-800 DEG C and preserving the temperature for 1-10 minutes; and cooling and then removing a phosphorosilicate glass layer. The invention has short process time, low cost and good gettering effect.

The invention discloses a conveying and impurity adsorbing device for melt-blown cloth production. The device comprises a bottom plate, wherein a box body is fixedly mounted at the top of the bottom plate, a first cavity and a second cavity are formed in the box body, a feeding port is formed in the inner wall of the side, away from the second cavity, of the first cavity, the inner walls of the sides, close to each other, of the first cavity and the second cavity are provided with the same communication hole, the inner wall of the side, away from the first cavity, of the second cavity is provided with a discharging port, the two sides of the box body are both rotationally provided with first guide rollers, and two second guide rollers and two third guide rollers are rotationally mounted in the first cavity. The conveying and impurity adsorbing device is reasonable in design and good in practicability, the upper surface and the lower surface of melt-blown cloth can be subjected to impurity adsorbing cleaning at the same time, the impurity adsorbing cleaning effect on the surface of the melt-blown cloth is better, the melt-blown cloth is cleaned more thoroughly, the melt-blown cloth can be flattened, the phenomenon that the melt-blown cloth wrinkles is avoided, and the production quality of the melt-blown cloth is improved.

The invention discloses a novel railboat for diffusing silicon wafers. The silicon wafers are placed on the novel railboat. The novel railboat for diffusing the silicon wafers comprises a boat body, at least three clamping grooves for containing the silicon wafers are formed in the boat body, the distances between any one of the clamping grooves and adjacent clamping grooves are L1 and L2, L1 is larger than L2 or L2 is larger than L1, and the clamping grooves are arranged at the intervals of L1, L2, L1, L2 in sequence. L2 is 1/2-1/7 of L1, or L1 is 1/2-1/7 of L2. Due to the fact that the distance of the front faces of the silicon wafers is not changed, the uniformity of diffusion is not influenced by the novel railboat. The structure of the novel railboat is combined with an insertion mode, compared with the railboat with an ordinary traditional structure being combined with the insertion mode, the novel railboat has the same gettering effect with a traditional insertion mode a, is higher in battery efficiency and productivity. The ordinary railboat can not meet the requirements of battery efficiency and productivity at the same time, while the novel railboat with the strucuture being combined with the insertion mode can meet the requirements of battery efficiency and productivity at the same.

The invention relates to a gettering method through implantation of carbon ions. The method comprises the following steps that high-energy carbon ions are implanted on an exposed layer on the back face of a silicon wafer or a silicon dioxide layer on the back face of the silicon wafer by the adoption of the ion implantation process, and a crystal defect area is formed on the implantation layer of the silicon wafer; the annealing is carried out, the crystal defect area is converted to be a gettering area, and metal ions in the silicon wafer are captured to form an impurity removing area; the impurity removing area is removed according to the chemical and mechanical grinding method. The ion implantation gettering process and the manufacturing process of a photodiode are high in compatibility and can be easily added into the prior art, the carbon ion implantation has no side effect on the performance of a device, and the device is not polluted in the gettering process of the ion implantation; meanwhile, the ion implantation gettering process parameters are optimized and controlled, so that the metal ion gettering effect is good, the performance of the gettered photodiode is better remarkably, dark current and white pixels are reduced remarkably, and the imaging effect of a CMOS sensor is improved.

The invention provides a multi-functional short-staple rope twisting machine. The multi-functional short-staple rope twisting machine comprises anti-slip mats, left supporting legs, right supporting legs, a machine base, a U-shaped supporting frame, a rope twisting motor, a rotary disc, a linear sliding rail, U-shaped sliders, winged screws, rope twisting hooks, a rope taking and wheel replacing structure, a structure for coiling a rope after rope twisting, a rope twisting length measurement determining rail structure and an anti-overflow shield structure, wherein the anti-slip mats are transversely glued to the lower surfaces of the horizontal sections on the lower portions of the left supporting legs and the lower surfaces of the horizontal sections on the lower portions of the right supporting legs respectively. Due to the arrangement of a fixing rod, a movable sleeve, a fixing hook and a square-head bolt, the moving position of the fixing hook is easily adjusted according to the horizontal requirements of rope twisting, and it can be ensured that rope twisting work is smoothly conducted; due to the arrangement of an adjusting slider, a stainless steel sliding rail, a measurement ruler and an adjusting bolt, the rope twisting length is easily ensured, and the rope twisting length consistency can be ensured.

The invention discloses an aluminum and boron common gettering method for a silicon wafer, which comprises the following steps of: preparing a boron-doped aluminum source; cleaning a silicon wafer; forming a boron-aluminum layer on the surface of the silicon wafer by utilizing a film plating technology; annealing at one step or multiple steps; and removing the surface layer of the silicon wafer. The invention utilizes the characteristic that the boron has higher solid solubility in silicon relative to aluminum, dopes the boron into the aluminum and dopes the boron into a heavy doped layer in the alloying process of the aluminum and silicon to obtain an aluminum-boron common gettering layer with high doping concentration. The aluminum and boron common gettering method of the invention can form the gettering layer which is deeper and even and has higher doping concentration at same annealing temperature and achieve the gettering effect of other processes at lower temperature and reduce the influence of high temperature on the performance of the silicon wafer. The aluminum and boron common getteirng method of the invention has the characteristics of low cost, easy operation and good gettering effect and has wider application prospect.

The invention relates to a silicon-based heterojunction solar cell structure and a preparation method thereof, the silicon-based heterojunction solar cell structure comprises an N-type monocrystalline silicon substrate, the front surface of the N-type monocrystalline silicon substrate is provided with an n + doping layer, a first intrinsic amorphous silicon/microcrystalline silicon film is deposited on the surface of the n + doping layer, no less than two layers of n-type amorphous silicon/microcrystalline silicon films are deposited on the surface of the first intrinsic amorphous silicon/microcrystalline silicon film, and a layer of first conductive film is deposited on the surface of the outermost layer of n-type amorphous silicon/microcrystalline silicon film; and a layer of second intrinsic amorphous silicon/microcrystalline silicon film is arranged on the back surface of the N-type monocrystalline silicon substrate, no less than two layers of p-type amorphous silicon/microcrystalline silicon films are deposited on the surface of the second intrinsic amorphous silicon/microcrystalline silicon film, and a layer of second conductive film is deposited on the surface of the outermost layer of p-type amorphous silicon/microcrystalline silicon film. The n + doping layer is formed on the main surface of the N-type monocrystalline silicon substrate to form a high-low junction, so that a certain separation effect on photon-generated carriers is achieved, and recombination of the photon-generated carriers is reduced.

The invention discloses a diffusion process for making solar cells, comprising the following steps: controlling the temperature inside a furnace at 840 DEG C; feeding oxygen at 200-500ml/min and small nitrogen at 700-1000ml/min under the temperature, and feeding big nitrogen at 10000-15000mL/min, wherein the duration is 8-12min; continuing feeding oxygen at 200-500ml/min and small nitrogen at 700-900ml/min, and feeding big nitrogen at 10000-15000mL/min, wherein processing lasts 11-16min; stopping feeding phosphorus source, reducing the temperature to 700-780 DEG C in 25-40min, continuously feeding oxygen at 2000-2500ml/min and feeding big nitrogen at 10000-15000ml/min in the whole cooling process, and then taking a silicon wafer out. The problem that ohmic contact difference is caused by too much reduction of the phosphorus concentration in the diffusion process and the problem that the uniformity is poor due to the difference between crystal boundary and crystal lattice positions on polycrystalline silicon in phosphorus source absorption in the prior art are solved.

The invention discloses a preparation method of an insulating SOI material, which comprises the following steps of: absorbing Cu impurities in bulk silicon and SOI material by a nano cavity caused byhydrogen ion implantation and helium ion implantation, respectively introducing the nano cavity formed by helium ion implantation into the SIMOXSOI material and the Smart Under the oxide buried layerof cut SOI material, there is little difference in the distribution of oxygen-rich buried layer after high temperature annealing. During annealing, the interaction of vacancy and hydrogen induced by hydrogen implantation will increase the diffusion rate of oxygen and form a wider oxygen-enriched region. After oxygen ion implantation, hydrogen ion implantation with high dose will be disadvantageousto the formation of continuous oxidized buried layer. The preparation method of the insulating SOI material has certain gettering effect on Cu due to the buried layer interface of the SIMOX material,but the gettering efficiency is low and the gettering is unstable at high temperature, while Smart The buried interface of cut SOI is more perfect than that of SIMOX SOI, and the gettering effect ofnano cavity layer is more obvious than that of SIMOX SOI. Two gettering sites, cavity layer and Al metal precipitation layer, were introduced into the same silicon substrate for the first time, and the gettering effects of two gettering methods on Cu impurity were compared.