Method for producing monocrystal wafers
FIELD: optoelectronics; producing wafers from ingots or bullions of monocrystals, such as sapphires.
SUBSTANCE: ingots or bullions are subjected to X-ray analysis to determine direction of cutting and at least one oriented flat is made thereon by grinding at its faces (0001). Then deviation from desired position is measured by means of diffraction meter and grinding process is repeated until deviation shorter than 3 minutes is attained. Cylinder blank is cut from monocrystal ingot or bullion perpendicular to at least one flat with distinct face on its surface. Then ends of cylinders are ground at 3-minute precision of their deviation from desired value. After that cylinder diameters are calibrated and base cut is made on each cylinder. Cylinders are annealed at 1300-1500 °C for minimum 8 hours. Upon cutting cylinder blanks into wafers annealing is repeated. Wafers are thinned by grinding and annealed under same conditions as cylinders.
EFFECT: ability of producing thin sapphire wafers at high precision with respect to diameter and thickness.
10 cl, 6 dwg
The invention relates to methods for producing wafers from ingots (boules) single crystals, for example, sapphire.
The known method of cutting single crystals and other brittle materials. The essence of the invention consists in the following. The single crystal is fixed on the substrate, serves on the steel tape mounted on the frame of the machine and reciprocating motion in the cutting zone serves the abrasive slurry on both sides of the cut single crystal in the direction of movement of the cutting cloths set the bars, the axis of which is perpendicular to the direction of movement of the cutting of the paintings, and their height is 0.5-5.0 mm greater than the height of the cut single crystal. The bars are rectangular profile or trapezoidal profile, where one lateral side facing the cut of the crystal, perpendicular to the bases, and the other rejected from the first angle of 5-10°, bars strengthen on the substrate a smaller base (see description to the patent of Russian Federation №2167055, IPC728 D 5/04, publ. 20.05.2001 year).
A known method of manufacturing semiconductor wafers. It includes the calibration of the single crystal, the manufacturer of the primary and secondary slices, cutting on single crystal plate, the calibration of the single crystal to the diameter of at least 2 mm more than the diameter of the plates, making the cutoff length L = L=l D/d, where l is the length of the slice on the plate; D - diameter of the calibrated crystal, d is the diameter of the plates, and after cutting a single crystal on a plate centering of the latter relative to the main edge, and an additional calibration to a given diameter plates (see description to the patent of Russian Federation №2105380, IPC6H 01 L 21/302, publ. 20.02.1998,).
A known way to produce sapphire wafers with a high degree of accuracy by linear and circular sizes.
The task and the technical result is to eliminate this drawback, namely the obtaining of thin plates of sapphire is made with fine precision in diameter and thickness.
This technical result is achieved in that in the method of manufacturing wafers of single crystals of sapphire, including calibration blanks of the single crystal diameter, the manufacturing base of the slicer and cutting blanks of the single crystal plates and inspection of geometrical and electrical parameters, in the beginning produce x-ray analysis to determine the direction of the cut and create on the ingot or bule crystal by willfully at least one oriented platform for faces (0001), and then using a diffractometer measure the deviation from the predetermined orientation and repeat the process fillipovcy to achieve a deviation of less than 3 minutes, p is izvodyat cutting blanks cylinders from ingots or boules of single crystal perpendicular at least one flat "platform" with a clear face on its surface, then produce grinding of the ends of the cylinder with the precision of a deviation from the target is less than 3 minutes, after which produce the calibration of the diameter of the cylinder, is made on each of the cylinders of the base slice and produce annealing of the cylinder at a temperature of 1300-1500°C for at least 8 hours, and after cutting of material on a plate cylinder produce re-annealing, the thinning of the wafer polishing and final annealing at the same modes as the annealing cylinders.
In addition, the thinning of the grinding plates are produced in two stages - first diamond shlifovalnyh with the associated abrasive with a grain size of 80 to 100 microns, then the diamond shlifovalnyh linked with the abrasive grain size 20...28 microns.
In the particular case after grinding the associated abrasive produce free abrasive grinding of boron carbide with a grain size <10 μm.
In addition, oriented ends with an accuracy deviation of less than 3 minutes made by fixing the workpiece in the fixture in the form of high-precision area, mounted on surface grinding machine, willfully one of the ends, measuring the deviation of the edge from a given orientation within less than 2 minutes and dolefully to get the desired result, the second end of the workpiece visitvisit parallel to the first.
In addition, cutting blanks cylinders produced by the drive ring diamond drill by fixing ingot (Buli) oriented "platform" on fine steel tile mounted on the table of the drilling machine.
In addition, the base shear is produced by mechanical fillipovcy diamond tool on the calibrated cylinder, clamp in vise surface grinding machine, after which produce control electrophysical parameters.
In addition, after cutting plates produce washing, visual check for chips and cracks and selective control of the orientation of the crystallographic lattice.
In addition, after thinning the wafer by grinding produce their cleaning and visual check for chips and cracks, scratches, scratches and negoslavci.
In the particular case of the complete method visual inspection of polished plates hold on "clearance" with the placement of the light source under controlled plate, and after cutting perform visual inspection and random inspection of the orientation of the crystallographic lattice.
Also, before annealing polished plates on them make the chamfer, and the control of geometrical parameters of the fabricated wafer is produced by measuring the thickness, thickness variation of deflection and warpage.
The inventive method is illustrated in the drawings, where figure 1-3 shows the device for orientation distinct faces of the ingot (Buli) and fillipovcy oriented "platforms", figs.4, 5 - fixture for accurate which the processing ends of the cylinders of single crystals, figure 6 - chart annealing cylinders and plates.
A method of manufacturing wafers of single-crystal sapphire is as follows. After growing a single crystal of sapphire (ingots, boules), and determine its suitability for manufacturing plates produce x-ray analysis using x-ray diffractometer type "DRON-6 to determine the direction of the cutting cylinder from it.
Then create a focused plane (0001) on the ingot (boules). On the surface of the ingot (Buli) there is a place with distinct edges (0001) plane sites. The cutting cylinder is perpendicular to these planes. The accuracy of the right angle should be the maximum.
For this ingot (Buhl) is mounted on the fixture - precision steel platform (Fig.1-3), the thickness of which shall not exceed 15 microns. The device consists of a housing 1 with welded thereto arcuate brackets, 2 to the body 1 from the bottom is rigidly attached to the longitudinal guide 3 and the transverse guide 4. In the bracket and screwed into the housing screws 5 and 6. Ingot (Buhl) sapphire 7 is installed in the fixture with the possibility of changing its spatial position and fixation using a series of screws 5. Further, the level of high precision face (0001) are placed parallel to the subject table of the drilling machine, i.e. the perpendicular is about visualisasi "the crown". Then the above device together with the ingot (boules) is installed on surface grinding machine and visitwales "Playground" on sides (0001). Then using a diffractometer type "DRON-6 (or any other) measures the deviation from the predetermined orientation. When the need becomes amendment and visitwales again. Upon reaching the deviations less than 3 minutes this operation is finished and the ingot (Buhl) is removed from the device and transferred to the next operation.
After surgery sanding awkward ingot (Buhl) oriented "platform" is mounted on precision steel "tiles", which is installed on the object table of the drilling machine and is directly the operation of the cutting ring diamond drill diameter.
To cut the cylinders must be manufactured oriented ends with the precision of a deviation from the target is less than 3 minutes. To do this, use a technological device in the form of high-precision area (figure 4, 5), and whose side is strictly perpendicular deviation angle from 90° less than 0.5 minutes from the outside and from the inside. The area consists of the area 8, in the vertical part of which is made horizontal slot 9 under the yoke 10. Along the axis of the vertical part of the area is screwed into the screw 11, rests in the affected clamp 10 with a screw Berezhany cylinder 13. The cut cylinder 13 long surface attached to the vertical part of area 8 to the sample 14, the vertical part of the area with the help of the clip 10 (or glue). Then the fixture is the area of the horizontal part is installed on the magnetic plate 15 surface grinding machine and visitwales one of the ends, then without removing the cylinder device, measured diffractometer "DRON-6" deviation butt from a given orientation, i.e. less than 2 minutes. In case of excess is an amendment and grind again until you get the desired result. The second end visitwales strictly parallel to the first. After fillipovcy of the ends of the cylinder to produce a calibration of the diameter.
Calibration of the diameter is performed in the standard way, as in metal working according to the instructions of cylindrical grinding machine.
The manufacturing base of the slice is performed using curved beads. Calibrated cylinder is clamped in the vise along the length of the cylinder, a vise mounted on a magnetic plate surface grinding machine and visitwales basic slice with validation using diffractometer "DRON-6".
Made the cylinder is in a state of stress. Therefore, it is necessary to perform the operation of relaxation (i.e. stress relieving), which is achieved to a certain extent of heat treatment (annealing).
Operation from the yoke is held at the operating temperature of 1300-1500° C for at least 8 hours.
The temperature of 1300-1500°is first critical to the crystal lattice, i.e. at this temperature, the lattice starts to "wobble", which leads to stress relief. The annealing operation is performed in the atmosphere in a muffle furnace in the next mode. After annealing cylinders produce cutting it on a plate, for example, by means of machine DWT, washing plates, a visual check for chips and cracks and selective control of the orientation of the crystallographic lattice using a diffractometer type "DRON-6, or any other device.
Visual inspection is conducted on a "gap", i.e. the illuminator is located underneath controlled plate. Above the plate is a magnifying glass 3x. This method is very well identified defects made by machining, cutting, grinding.
The cut plate, as well as polished, are in a state of stress and due to growth defects, uniform in hardness. At the boundaries between raznocvetnimi plots cracks, and the plate is falling apart. Moreover, the grinding plate surface is treated unevenly, which leads to thickness variation in excess of the necessary requirements. The annealing operation relieves tension and makes the plate is homogeneous is vergoti.
The annealing operation is conducted in a container for annealing wafers produced, for example, of sapphire in a muffle furnace.
After annealing produce control electrophysical parameters by measuring the thickness, thickness variation, bending and warping of the plate using measuring geometrical parameters "Tropal and tunnel microscope. Measurement data are entered into the database.
Then produce a thinning of the sapphire wafer.
The thinning of the wafer is performed in two stage grinding machine with diamond pills.
1st stage - grinding diamond shlifovalnyh with a grain size of 80 μm; 2 stage grinding diamond shlifovalnyh with a grain size of 20 μm to 28 μm.
The introduction of two-stage grinding associated abrasive eliminates one stage of free abrasive grinding, which reduces the grinding operation, increases productivity by approximately 25% and eliminates one washing operation between the two stages of processing free abrasive.
For large items can be entered for the free abrasive grinding of boron carbide with a grain size <10 micron for grinding machine "Peter Wolters F 700".
After grinding produce washing plates on the washing line type ULRASONIC MN - 5MW18D, visual inspection for chips, scratches, scratches, cracks and negoslavci and using the processing tank chamfers plates produce processing chamfers plates with subsequent washing on the washing line type ULRASONIC MR-5MW18D.
Polished plates are in a state of stress, so their final annealing in the same modes as the annealing calibrated cylinder.
After annealing to produce a final inspection of geometrical parameters of the meter, laser marking with outside parties.
The claimed method allows to obtain high quality sapphire wafers suitable for use and meet the high requirements of modern optoelectronics.
1. A method of manufacturing wafers of single crystals from ingots or boules, including calibration blanks of the single crystal diameter, the manufacturing base of the slice, cutting blanks of the single crystal plates and inspection of geometrical and electrical parameters, characterized in that in the beginning produce x-ray analysis of the ingot or the single crystal boules for determining the direction of the cut and create on it willfully at least one oriented "platform" on sides (0001), and then using a diffractometer measure the deviation from the predetermined orientation and repeat the process fillipovcy to achieve a deviation of less than 3 min, produce cutting blanks cylinders from ingots or boules of single crystal perpendicularly at least one flat "platform" with a clear face on its surface, and then produce sections is at the ends of the cylinder with the precision of a deviation from the target is less than 3 min, then produce the calibration of the diameter of the cylinder, while the base cut is made on each of the cylinders and produce annealing of the cylinder at a temperature of 1300-1500°C for at least 8 h, and after cutting of material on a plate cylinder produce re-annealing, the thinning of the wafer by grinding and final annealing at the same modes as the annealing cylinders.
2. The method according to claim 1, characterized in that the thinning of the wafer by grinding to produce at least two stages - first diamond shlifovalnyh linked with the abrasive grain size 80÷100 μm, then the diamond shlifovalnyh with the associated abrasive with a grain size of 20÷28 microns.
3. The method according to claim 2, characterized in that after grinding the associated abrasive produce free abrasive grinding of boron carbide with a grain size <10 μm.
4. The method according to claim 1, characterized in that the grinding oriented ends of the cylinders with an accuracy deviation of less than 3 min exercise when attaching the cylinder device in the form of high-precision area, installed on a surface grinding machine, by fillipovcy one of the ends, measuring the deviation of the end from the predetermined orientation within less than 2 min and dolefully to get the desired result, the second end of the workpiece visitvisit parallel to the first.
5. The method according to claim 1, distinguished by the different topics that cutting blanks cylinders produce a ring with a diamond drill when attaching the ingot g or boules oriented "platform" on fine steel tile installed on the table of the drilling machine.
6. The method according to claim 1, characterized in that the base cut is made on the calibrated cylinder clamped in the vise surface grinding machine by mechanical fillipovcy diamond tool, and then produce control electrophysical parameters.
7. The method according to claim 1, characterized in that the cutting cylinder to the plate and produce their washing, visual check for chips and cracks and selective control of the orientation of the crystallographic lattice.
8. The method according to claim 1, characterized in that after thinning the wafer by grinding produce their cleaning and visual check for chips, cracks, scratches, scratches and negoslavci.
9. The method of claim 8, wherein the visual inspection of polished plates hold on "clearance" with the placement of the light source under controlled plate, and after cutting perform visual inspection and random inspection of the orientation of the crystallographic lattice.
10. The method according to any one of claims 1 to 9, characterized in that before annealing polished plates on them make the chamfer, and the control of geometrical parameters of the manufactured plates producing the measurement of the thickness, crown, deflection, and warpage.
FIELD: electronic engineering; production of photomask blanks.
SUBSTANCE: proposed method for producing photomask blanks includes mechanical and chemical treatment of glass wafers, their placement in vacuum chamber, and coating with masking chromium layer by heating chromium-containing evaporator in nitrogen environment until desired optical density is attained, this being followed by wafer washing, covering with resist, and control. Chromium is cleaned prior to being applied to masking layer by remelting it at temperature of 2000 to 2100°C and residual pressure of 400 - 500 mm of mercury in argon environment; chamber is cooled down to room temperature, evaporator is heated at a rate of 500 - 700°C a minute to 1700 - 1850°C, exposed to this temperature for 25 - 35 minutes, then evaporator is heated to 1860 - 1950°C and chromium is evaporated at a rate of 140 - 160Å a minute until desired optical density is attained.
EFFECT: enhanced quality of varying-reflectance masking layer and environmental friendliness of method.
4 cl, 1 tbl
FIELD: treatment of semiconductor wafer surfaces, such as their chemical and mechanical polishing followed by washing them.
SUBSTANCE: proposed device has chemical-mechanical polishing mechanism, vertical displacement mechanism with magazine holder installed for step-by-step vertical displacement of magazines, robot-manipulator provided with wafer grip, two wafer transfer robots, and wafer washing plant. Magazine holder of vertical displacement mechanism is made in the form of hollow shaft mounted on top end of spline shaft for its turning through 360 deg. from drive; bottom end of hollow shaft mounts n magazine intake platforms, where 1 < n ≤ 4; axes of magazine intake platforms are spaced 90 deg. apart and bottom ends of intake platforms carry guides with slots similar to and coaxial with magazine slots. Magazine holder is installed in detergent tank; wafer grip of robot-manipulator is made in the form of removable ring whose top part is beveled to receive wafers and spring-loaded restricting pins. Wafer grip of robot-manipulator is provided with spray nozzles installed on top and below the ring.
EFFECT: reduced labor consumption for device manufacture due to its reduced size.
1 cl, 3 dwg
FIELD: machining semiconductor wafers.
SUBSTANCE: proposed machine tool designed for circular machining of semiconductor wafers to produce wafers having side surfaces of desired shape with minimal quantity of post-machining circular scratches and to execute great number of process operations without displacing wafers from one position to other has pair of supporting and driving rollers that function as supports for vertically disposed semiconductor wafers and are set in motion by means of drive belt connected to them. Machine tool also has two opposing movable wafer-machining units each incorporating first and second members designed for machining wafers when they are installed in first and second positions. Second design alternate of semiconductor wafer machine tool and self-aligning arbor fastening assembly is also proposed.
EFFECT: enlarged functional capabilities of machine tool, improved quality of post-machining side surfaces of wafers.
22 cl, 17 dwg
FIELD: thermochemical etching.
SUBSTANCE: method comprises etching the surface of articles made of high-melting chemically stable materials by applying the layer of an agent interacting the article material and heating the surface by laser pulse irradiating. The surface of the article is simultaneously affected by the laser pulses and vapors of a volatile composition, which is subjected to the pyrolytic decomposition to produce the above mentioned material. The amplitude of the laser pulse should be sufficient to cause the evaporation of the material.
EFFECT: enhanced adaptability to shaping.
FIELD: semiconductor engineering; manufacture of extremely thin semiconductor structures and diaphragms.
SUBSTANCE: proposed method includes sticking of wafers and locking plates on faceplate using hold-down devices and separate mechanical treatment of plate and wafer surfaces to attain their desired definite thickness; faceplate is provided with at least two areas for sticking wafers and plates separated by blind slots; stuck to one of these areas are plates made of material whose hardness is greater than that of semiconductor wafer material; locking plates are mechanically finished and semiconductor wafers are stuck to free area of faceplate without changing position of pre-treated locking plates on faceplate. Adhesive used for sticking locking plates has melting point higher by at least 15 - 20 °C than that of adhesive employed for sticking semiconductor wafers. Locking plates are stuck using hold-down device independent of that used for semiconductor wafers.
EFFECT: enhanced quality and precision of treatment of semiconductor wafers.
3 cl, 4 dwg
FIELD: machine engineering, namely apparatuses for drilling articles of soft non-metallic materials, of semi-precious and commercial stones.
SUBSTANCE: machine tool includes housing, spindle unit, drive motor for driving machine tool mechanisms, reduction gear, camshaft, manipulator with tail spindle for clamping and rotating blank. Rotation drive unit of manipulator and tail spindle is in the form of block onto which thread is wound; one end of said thread is spring loaded; its other end is joined with pusher engaged with cam of camshaft.
EFFECT: simplified design, improved operational reliability of machine tool.
FIELD: mechanical engineering; devices and methods for separation of materials.
SUBSTANCE: the invention is pertaining to the device and the method for separation of materials, in particular, to monocrystals. The technical result of the invention is effective purification and removal of the stripped material during the cutting. For this purpose the device contains: a rotary cutter with a concentric hole, the edge of which forms the cutting edge, at that the rotary cutter is made with a capability of rotation around its central shaft for cutting of the material; a position device intended for positioning of the material subjected to cutting in respect to the rotary cutter in such a manner, that during the cutting process the cutting disk is moving across the material making rotation for cutting-off a separate plate; a device for feeding a lubricating-cooling liquid onto the rotary cutting disk and a device for feeding a gaseous medium onto the rotary cutting disk. At that the device for feeding the gaseous medium has a nozzle, which is mounted inside the concentric hole and is designed in such a manner, that the gaseous medium is fed onto the edge in the direction perpendicular to central shaft of the rotary cutting disk. The method provides for feeding of the lubricating-cooling liquid only onto the outlet side of the cutting disk if to look in the direction of its rotation behind the place of the rotary cutting disk pass through the material. At that the rotary cutting disk is subjected to cooling during operation of the cutting, and the plate is cooled only after operation of the cutting after the separate plate has been cut off during operation of the cutting. At that during the cooling operation the lubricant-cooling liquid is fed by the batching amounts, and during the stripping operation the lubricant-cooling liquid is fed in the bigger amount as compared with the indicated above amount.
EFFECT: the invention ensures the effective purification and removal of the stripped material during the cutting operation.
12 cl, 6 dwg
FIELD: technology for processing diamonds into brilliants.
SUBSTANCE: in the method, by experimental or calculation-theoretic way in glow images visible to observer optical characteristics of diamond glow are determined, including glow intensiveness, glow glimmer and color saturation of glow, characterized by level of decomposition of white color on rainbow colors, and also relief coefficient of glow, characterized by average number of intensive color spots in glow image, distinctive to human eye, and additionally, by dividing glow image on compound portions, average values of glow intensiveness of compound portions are measured. Optical characteristics of glow are transformed to glow factors. As average coefficient of brilliant glow charm, which is used to estimate brilliant glow charm, charm coefficient is used, calculated as average value of factors of intensiveness, glimmering, color saturation and glow image geometry.
EFFECT: possible objective measurement and numeric estimation of brilliants glow charm, and possible certification of them on basis of glow charm.
5 cl, 22 dwg, 11 tbl
FIELD: working stone.
SUBSTANCE: machine-tool comprises units for sawing arbitrary stones into thin-walled plates in rotatable vice, copying, and polishing and mechanism for changing units made of carriage with the horizontal axle in the top section. The desirable unit is set in the working zone by means of rotation around the axle, while the remainder units are positioned vertically in the waiting zone.
EFFECT: expanded functional capabilities.
2 cl, 17 dwg
FIELD: mechanical engineering, in particular, manufacture of machines for mechanical treatment of stones, in particular, for drilling of amber products.
SUBSTANCE: each working position of the set is provided with the second spindle box located opposite the first one. The drills in the spindle boxes are installed coaxially. The rotor set is provided with a fixture for monitoring the integrity and blunting of the drills including two pickups of electron optics coupled via an electronic unit with a fixture for refusal from feed of the working positioned by blanks. Each pickup is fastened on a lever mounted on a post for turning, and is installed so that it checks the drills after the drilling is over at displacement of the working position. The fixture for fastening the products under treatment is installed for vertical motion.
EFFECT: enhanced capacity of the set and prevented reject.
FIELD: manufacture of semiconductor components and devices.
SUBSTANCE: method for dividing mono-crystal such as GaAs comprises steps of cutting mono-crystal at least by two portions, providing motion of cutting tool (2,3; 8,8w, 8b, 8c) relative to mono-crystal in direction of motion (V); orienting mono-crystal 1 in such a way that to arrange predetermined crystallographic direction (K) in cutting plane (T); selecting angle (ρ) between predetermined crystallographic direction (K) and motion direction (V) in such a way that to provide mutual compensation of forces acting upon cutting tool at cutting process in direction normal relative to cutting plane or providing said forces equal to predetermined value.
EFFECT: increased cutting speed, enhanced quality of wafers allowing omit further working operations of them.
16 cl, 12 dwg
FIELD: mechanical engineering.
SUBSTANCE: automatic drilling machine comprises housing, two spindle units with drills, mechanism for clamping article, cam for machine feeding mechanism, feeder, and chute for receiving the finished articles. The two spindle units with drills and mechanism for clamping article are made of single kinematic chain. The chain is arranged along the axis of drilling for permitting co-operation with the cam. The spindle units are built in the bushings spring-loaded with respect to the housing. The mechanism for clamping blanks is made of a guide and clamping bushing spring-loaded with respect to the housing. The feeder is made of a pipe with hole for feeding and removing article under its own weight. The feeder is interposed between the guiding and clamping bushings and is secured to the latter one. The first spindle unit is provided with the stop. The second spindle unit has rod which allows the drills to be spaced. The rigidity of the spring which spring-loads the guiding bushing is lower than that of the spring which spring-loads the bushing which receives the second spindle unit and is higher than that of the spring which spring-loads the pressing bushing.
EFFECT: simplified design.
FIELD: machine engineering, possibly finishing parts such races of precision bearing assemblies.
SUBSTANCE: method comprises steps of working rotating part with use of tool head with two blocks; mounting part in shaft of crank mechanisms while providing one freedom degree around center of said shaft; imparting to tool head circular motion in axial plane of part at self-aligning blocks relative to center arranged in symmetry plane of finished surface. Such procedures provide symmetry of finished part profile.
EFFECT: enhanced efficiency, improved quality of finishing part.
2 dwg, 1 ex