9results about How to "Reduce memory effect" patented technology

The invention provides an epitaxial growth process for improving doping uniformity of n-type doped silicon carbide, and relates to the technical field of semiconductors. The method is based on a chemical vapor deposition growth technology; 11 to 20 gt; the silicon carbide epitaxial growth is carried out by taking silicon carbide with a 4-degree silicon surface in the direction as a substrate, taking trichlorosilane (TCS) and ethylene (C2H4) as growth sources and taking ammonia gas (NH3) as a doping source. Ammonia gas is adopted as an n-type dopant, the decomposition efficiency of the n-type dopant is close to 100% at the temperature of 700 DEG C or above, and the energy of N-H bond breakage of ammonia gas molecules is 390 KJ / mo which is far lower than 946 KJ / mo needed by N-N bond breakage of nitrogen molecules. Therefore, compared with a traditional doping source such as nitrogen, the ammonia gas has higher doping efficiency, residues of excessive nitrogen-containing precursors in the reaction chamber can be reduced, the memory effect is reduced, and thus more excellent in-chip uniformity and stable inter-chip repeatability of the epitaxial wafer are obtained. The selection range of the doping source is widened, the accurate control of the doping concentration is realized, and the stability of the doping concentration in the continuous growth process is improved.

The utility model provides a high-melting-point graphite pipe for elemental analysis, which belongs to the technical field of spectral analysis and comprises a circular hollow graphite pipe main body and transverse support parts symmetrically arranged on two sides of the graphite pipe main body, an inner pyrolytic carbon layer is deposited on the inner wall of the graphite pipe, a porous structure is arranged in the inner pyrolytic carbon layer, and an outer compact pyrolytic carbon layer is further deposited on the surface of the inner pyrolytic carbon layer. Through the inner pyrolytic carbon layer and the outer compact pyrolytic carbon layer, in the high-temperature working process, the inner wall pyrolytic carbon layer can be selectively consumed to form a compact glassy carbon film, a self-adaptive protection mechanism enables the graphite tube to still keep stable analysis performance under extreme conditions, reaction or permeation of a detected element and graphite at high temperature is reduced, and the analysis accuracy of the graphite tube is improved. The phenomenon of cross contamination is reduced, the memory effect of the graphite pipe is reduced by 70%, but the memory effect of a traditional pyrolytic graphite pipe can only be reduced by 30-40%, and the graphite pipe is particularly suitable for analysis of high-melting-point elements.

The integrated microfluidic detection chip comprises a liquid conveying channel, the upper end and the lower end of the liquid conveying channel are each provided with an inlet, the center position of the side end of the liquid conveying channel is communicated with a mixing channel, the other end of the mixing channel is communicated with a flow velocity difference channel, and the flow velocity difference channel is communicated with a flow velocity sensor. An electrode detection disc is arranged on the side face of the flow velocity difference channel in a communicating mode, and a circular barrier is fixedly arranged in the electrode detection disc. Compared with a traditional detection chip, the integrated microfluidic detection chip based on dual-channel flow velocity difference vortex enhancement has the following remarkable advantages: a breakthrough in mass transfer limit is achieved: through multiple physical coupling of dual-channel flow velocity difference, incident angle optimization and a circular barrier, substance transmission is converted from single molecule diffusion to active vortex driving; the bottleneck that mass transfer of a microfluidic system is limited is solved, and in-situ dynamic refreshing of a detection interface is realized by an automatically generated discrete sample injection mode.

This invention discloses a rapid on-site Raman detection method based on acoustic levitation-driven hotspot and molecular co-assembly, comprising the following steps: (1) forming a suspended droplet in a mixed liquid containing the analyte molecule and a nano-substrate in an ultrasonic standing wave sound field; (2) evaporating and concentrating the suspended droplet, and acquiring Raman spectral signals and monitoring the size of the suspended droplet in real time during the evaporation process; (3) determining the optimal value of the enhanced signal based on the real-time correlation between the size change of the suspended droplet and the Raman signal intensity, and realizing trace analysis. This invention enables on-site SERS detection of various toxic and harmful substances with ultra-high sensitivity, good reproducibility, and high detection throughput, significantly improving the performance of surface-enhanced Raman scattering detection.

The invention relates to the technical field of MOS (Metal Oxide Semiconductor) semiconductors, and discloses a voltage-withstanding MOSFET (Metal Oxide Semiconductor Field Effect Transistor) device for high-load shutdown of a robot dog and a preparation method thereof, the voltage-withstanding MOSFET device comprises a plurality of parallel MOS cells, and each MOS cell comprises a drain electrode, a semiconductor epitaxial layer, a source electrode and a grid electrode; the semiconductor epitaxial layer comprises an N substrate layer, an N drift layer, a P + layer, an N well layer and a P well layer, and a lightly doped N layer is arranged in the middle of the N drift layer of each MOS cell; laterally symmetrical L-type P-layers with inclined tops and arc-shaped opposite side tops are introduced to the two sides of an N drift layer, and in cooperation with the middle buffering effect of a lightly doped N layer, local electric field concentration at the edge of the N drift layer in a traditional device can be accurately dispersed; the arc-shaped and L-shaped contours defined by the photoetching process can effectively guide the electric field to be uniformly distributed, so that the breakdown risk caused by too strong local electric field is avoided.

The invention discloses an iodine impurity detection method based on inductively coupled plasma mass spectrometry, which adopts a diluent of a tetramethylammonium hydroxide system and a specific sample pretreatment process to effectively stabilize an iodine element and reduce a memory effect. Indium (In) is used as an internal standard, and detection is carried out in a collision reaction tank mode (He), so that the analysis accuracy, stability and anti-interference capability are remarkably improved. According to the detection method disclosed by the invention, the sample pretreatment process is simple and rapid, mild acid dissolution is combined with dilution of the diluent, so that the sample can be completely dissolved, the matrix effect can be reduced to the minimum, the linear relation is good, the precision is high, and the specificity is strong; the method is suitable for rapid and accurate determination of trace iodine impurities (the limit is not more than 50 [mu] g / g) in drugs and pharmaceutic adjuvants.

The embodiment of the invention relates to the technical field of solution treatment by adopting an ion exchange method, in particular to a method for determining components of a solution for removing boron and a method for reducing a memory effect of a boron isotope test by adopting the solution. In one aspect, the embodiment of the invention provides a method for determining components of a solution for removing boron, and the solution is suitable for removing boron residues in a pipeline of a mass spectrometer; in the second aspect, the embodiment of the invention further provides a method for reducing the memory effect of the boron isotope test, and the solution with the components determined according to the method in the first aspect of the application is adopted. By means of the method, the boron removal solution which can stably and effectively remove boron residues, cannot generate new residue problems and is short in consumed time can be obtained, in the boron isotope test, the solution is used for cleaning a pipeline, the boron residues of the last test can be rapidly eliminated, the situation that the boron residues interfere with the test result of the next test is avoided, and the test efficiency is improved. Therefore, the test memory effect is reduced, and the test precision is improved.

The application discloses a precision detection method for volatile heavy metal elements in metallurgical residual activated sludge, and belongs to the technical field of environmental monitoring and chemical analysis. The application optimizes a "HNO3-H2O2-HF" composite acid system combined with gradient temperature microwave digestion, can effectively destroy the complex mineral lattice of metallurgical sludge, release the wrapped heavy metals, ensure that the extraction rate is greater than 95%, and the result is closer to the true value. The addition of L-cysteine complex significantly improves the element stability, improves the atomization stability in ICP-MS, and reduces the memory effect. The microwave digestion is selected, the sample is subjected to in a closed system, the acid consumption is small, the waste gas emission is small, the use and exposure risk of HF are reduced. Subsequent low-temperature driving of hydrofluoric acid effectively reduces the volatilization of trace elements, and L-cysteine is used to protect the volatile elements, and the stability in the subsequent transfer, storage and detection process.

This invention belongs to the field of mass spectrometry technology, specifically providing a multi-mode mass spectrometer, including an ion source with a first inlet, an ion funnel including multiple electrodes, multiple isolators and a heating element, wherein the isolators are disposed between adjacent electrodes of the ion funnel and are insulated from adjacent electrodes, and the heating element is disposed on the isolators; a second inlet is disposed between the ion source and the ion funnel. This invention has advantages such as strong detection capability, strong anti-contamination capability, and high ion transmission efficiency.