CN102953123B - Sag resistance brake unit and the ultralow quality delivery system of side-wall heater diffusion furnace - Google Patents

Abstract

Multizone solaode diffusion furnace has multiple radiating element (SiC) or/and high intensity IR lamp heated type machining area, and region comprises baffle area, riser region, roasting region, soak zones and cooled region.Implement to transport through solar cell wafer the operation of stove by ultralow quality wafer delivery system, solar cell wafer, chip conveying system includes being spaced laterally apart, having protection and synchronously driven metal tape or chain, metal tape or chain and carries the non-rotating alumina tube being suspended on the tinsel between metal tape or chain.Wafer is positioned on the protruding circumference bearing being spaced laterally apart along alumina tube, reduces and pollutes.High intensity IR flux carries out quick light radiation regulation to wafer so that diffusion occur speed than the conventional high-quality fast twice of calorimetric stove more than.The longitudinal side wall heater using the Inco nickel sheath being inserted in transporting tube guarantees uniformly to heat the Waffer edge of adjacent sidewall, and heater includes coil heater.

Description

Sag resistance brake unit and the ultralow quality delivery system of side-wall heater diffusion furnace

Technical field

The present invention relates to continuous conveyor, multilane formula (multi-lane) diffusion furnace for by using at 700-1100 Radiation resistance in the range of DEG C is or/and solar cell wafer is processed by the heating of IR lamp, so that the combination of P and/or B adulterant Thing diffusion or/and in the silicon (or other advanced materials) that is diffused into altogether in wafer, is consequently formed p-n junction surface layer or/and back of the body table Face electric field layer.In particular it relates to a kind of solaode diffusion furnace, there is one or more heating region and ultralow Quality, low-frictional force, portion transverse wire suspension type alumina tube delivery system, add longitudinal side wall pharoid and sag resistance Brake unit molectron.

Background technology

Manufacture silica-based solar cell to need to get off thin slice silicon by " wire saw " transverse cuts from silicon ingot, be used for being formed slightly Rough solar cell wafer.Subsequently to these wafers (whether still being formed by the polycrystalline combined by crystal formation) It is processed the smooth wafer forming thickness in 140 to 330 micrometer ranges.Rare due to suitable silicon, trend is to make Wafer is thinner, and usual thickness is 140-180 micron.

Subsequently by completion raw wafers (raw wafer) be processed into can by photovoltaic effect produce electricity functional too Sun can battery.Wafer processing comprises: being referred to as the two stage process of diffusion, it produces semi-conduction " p-n " junction diode；Followed by Three techniques, are printed onto wafer on the front and back, then by silver and aluminum based sizing coated wire mesh the most respectively Burning till p-n junction grid and back contact, wherein these layers each act as ohm colelctor electrode and ground connection.

Diffusion technique generally comprises two stages: first stage is the front to wafer and/or backside coating (coating) The dopant material of one or more type also makes these materials be dried, and then, second stage is in diffusion furnace, room or the thermal treatment zone The wafer having been coated with is heated (roasting) by territory, so that adulterant compositions is diffused into silicon (or other advanced materials) wafer In substrate, thus form p-n junction layer or back contact.The present invention relates to the diffusion furnace that improves to some extent and roasting technique, process and Thermal profile.

In the case of having various phosphorus (P) or boron (B) source, at high temperature spread.Use phosphorus at the top surface of wafer Upper generation p-type is tied, and uses boron to produce N-shaped knot on the back surface.P-doped silicon (P-doped Si) forms " launching of photovoltaic cell Pole " layer, i.e. the layer of electronics is launched when being exposed to sunlight (conventional photon source).As it has been described above, through the metallic contact of silk screen printing Fine net collect these electronics, described metallic contact is to be sintered in the surface of battery by metallization stove.

Order about phosphorus by high-temperature diffusion process to enter in wafer.Current technique generally time-consuming 20-30 minute.Additionally " electroactive " phosphorus makes low resistance contact be formed.In common diffusion, coat boron compound to the back surface of wafer, and to crystalline substance The top surface phosphors coating compound of sheet.Wafer is heated by single roasting, in order to make the diffusion altogether of boron and phosphorus simultaneously In the basal surface and top surface of its correspondence.

It is being diffused and various cleaning, Laser edge ablation and etch process are to remove not from the two sides of wafer After the semiconductor junction needed, being coated described wafer with ARC (ARC) (typically silicon nitride (SiN3)), this leads to It is often to be carried out by plasma enhanced chemical vapor deposition (PECVD).After ARC coats, battery is navy blue surface Color (or brown, this depends on painting cloth material used).ARC makes the reflection of the incident photon of wavelength about 0.6 micron reduce to Low.Luckily the hydrogen being embedded in silicon due to the formation of ARC have the effect of dummy defect, and the especially body in polycrystalline material lacks Fall into.Described defect is some traps, and electron-hole pair can be recombinated in these traps, thus reduces battery efficiency or power is defeated Go out.

Metallizing in roasting process at IR subsequently, high temperature (more than 850 DEG C) can make hydrogen spread from wafer to go back.Cause This, in order to prevent described hydrogen from " exitting " from wafer, need roasting time shorter.Preferably hydrogen captured and stay in block materials (especially in the case of polycrystalline material).

The present invention relates to diffusion roaster and the diffusion technique improved to some extent.It is currently available for these diffusion roasting techniques IR carrier stove have long heating chamber, plurality of IR lamp chip conveying system (band of wire mesh or ceramic roller conveying Device) top substantially homogeneously separates (generally separate 1.5 ") with lower section.By various forms of insulation, it is most commonly that compression Type Masonite, makes heating region insulate with external environment condition.Infrared ray (IR) lamp makes the temperature of incoming silicon wafer be increased to About 700 DEG C to 950 DEG C.Within 30 minute persistent period of diffusion technique, keep this temperature, then make wafer cool down and incite somebody to action It is transferred to next downstream processing operations and equipment.

Currently available diffusion furnace generally uses one of two kinds of chip conveying system: 1) high-quality carrier, its Heavy type (> 350Kg including multiple static state (non-longitudinal movement)) solid ceramic rotating roller；Or 2) metal of movable (vertically moving) Mesh belt, is used for carrying the wafer roasting region by stove.In order to make the metallic pollution of wafer back surface reduce to minimum or prevent The metallic pollution of wafer back surface, presently preferred static ceramic rotary transfer roller stove.The working width of these stoves is usually 1 to 2 meters, permits Permitted wafer and be emitted on band or roller conveyor, being therefore referred to as " multilane formula " stove.Typical conventional diffusion furnace is about 400 " Long, " wide IR lamp is placed on above roller, and 100 to 160 lamps are placed on below roller 160 36.

In the static solid rotating roller carrier stove of these high-quality, the temperature of furnace chamber is increased to by IR lamp for a long time Diffusion temperature, diffusion temperature is in the range of 700 DEG C to 950 DEG C.Operating principle is obviously such that the IR lamp maintaining roller below roller Being hot, and wafer helps heat transfer to wafer with contacting of roller, this heat transfer is to be carried out by thermo-contact conduction.Along defeated Sending device to have significant thermal profile, it raises in porch and reduces in exit.

As for band of wire mesh carrier, it is necessary to band is supported in centre with quartz ampoule, in case leukorrhagia stopping is sagging and carries Slidingsurface for low-frictional force.Owing to pipe covers the downside of wafer, in order to prevent from occurring on wafer " cold " band, by pipe arrangement Become herringbone pattern.But, the price of pipe is the highest, makes the quality of conveyor system increase, and hinders the bottom entering stove to add Thermal region.

Therefore, solid rotary ceramic roller conveyor or the band of wire mesh stove of the present art cannot meet at control base Accelerate to produce and strengthen the demand of production capacity while building expense.In order to compensate, make stove the most wider, thus can be Each stove region processes the wafer of a plurality of circuit.This needs again longer, the higher lamp of price, the mean time to failure, MTTF of these lamps The most shorter, thus dramatically increase running cost.Equally, the power of lamp currently cannot be increased, this is because higher To may result in modulation element overheated in output, this be by the thermal mass of stove cause (mainly in high-quality solid ceramic roller conveyor system In system).Overheated in order to prevent, use thermocouple to reduce power density, but this spectrum output that IR lamp can be caused to launch occurs Substantial variations (relatively low luminous flux and energy output).The luminous flux result reduced needs again reduce the speed of carrier band or prolong The length (simultaneously maintaining original tape speed) of long stove, therefore makes processing slack-off.

Therefore, in the field of diffusion furnace and diffusion roasting technique, has following outstanding demand: significantly improve roasting The clean of region effectively uses, it is provided that more preferably controlling and thermal profile whole stove, it is allowed to improve the utilization of roasting energy, improves and expands The speed of day labor skill and uniformity, reduce the length of stove while production capacity keeping or improve, and occupies face at stove Long-pending reduce and energy, operation and maintenance cost lower in the case of realize these targets.

Summary of the invention

Present invention accomplishes these demands in this field, the present invention relates to multizone solaode diffusion furnace, institute State diffusion furnace and there is super low-quality movable delivery system, be used for carrying wafer by multiple heating and cooled region, described district Territory comprises one or more diffusion soak zones and optional of at least one inlet baffle region, riser region, followed by downstream Diffusion roasting region, and one or more cooled region, for phosphorus or/and the front of boron dope agent and/or back side diffusion or/and Diffusion altogether, thus in wafer substrate, form p-type or N-shaped knot and/or back contact.

Exactly, the present invention relates to the ultralow quality activity delivery system of wafer roaster, described delivery system comprises Sag resistance brake unit and side-wall heater, to guarantee that the wafer crossing the outside drawing lines along multi-thread tunnel-type is carried out uniformly Heating.

As herein as disclosed in example, two alternate embodiment illustrate the delivery system of the present invention: A) band/pin drive system；And B) roller chain/chain wheel drive system, its central roll chain/chain wheel drive system is presently preferred enforcement Example.In both embodiments, to be supported on the minor diameter hollow of non-rotating during longitudinally through machining area resistance to for wafer On fire tube, described refractory tube is to be carried on suspension wire or the bar of the width across delivery system.In band/pin drive system In, described opposite end wiry is by rack bearing, and described support is to be formed by drive belt or invest in drive belt.At roller In chain/chain wheel drive system, end wiry is arranged in the hollow pipe of chain link pivot.

In currently preferred heating system, top heating region uses transversal orientation Formulas I R lamp, and adds in bottom Thermal region uses the combination of IR lamp and resistance heating.In order to improve the Transverse Heated uniformity crossing over stove width, resistance is added Hot device is placed on and two longitudinal side wall adjacents, described sidewall be oriented to be parallel with stove centrage and with described centrage every Open, and IR lamp is laterally placed on above or below longitudinal side wall stratie, be preferably lower section.Longitudinal side wall resistance heats Device is arranged in quartz ampoule, earthenware or stablizes in SiC pipe, and described pipe is arranged in below carrier.At 5 drawing lines or broader In stove, described heater is in suitable diffusion temperature in order to keep the wafer in the row 1 and 5 adjacent with corresponding sidewall.This It is particularly suited for common diffusion processing.

The advantage using high intensity IR lamp isolation module is, it is provided that short wavelength, the regulation of high flux IR light, thus promotes Diffusion faster.In the present invention, it should be appreciated that mentioning high intensity IR lamp (HI-IR) part, SiC radiation/re-radiation can be used Heating element heater, the disclosure of HI-IR modulation element is only used as example.

By use ultralow quality, activity (vertically moving), the delivery system that has protection in stove region, implement advanced person The transport of materials for solar cells wafer (such as, silicon, selenium, germanium or gallio solar cell wafer), described delivery system includes Two or more continuous loops transporting element being spaced laterally apart, described transport element is included in wafer processing travel path " carrying " of narrow width on every side, described band load capacity is light, diameter is little, the refractory tube of non-rotating, and described refractory tube is It is suspended on the tinsel tied up between described band.Described refractory tube is thin-walled, hard pottery or vitreous material, preferably For at least one in aluminium oxide, silicon dioxide, zirconium oxide.

Implementing delivery system with many one exemplary embodiment " to carry ", Section 1 is metal, the horizontal orientation being spaced laterally apart Flat belt or belt, each band has multiple vertically extending support, described support along band longitudinally spaced.Described support holds Carry tinsel, described tinsel is installed with refractory tube.Described tinsel coupling support to (the upper support of each band) it Span wafer row inbound path horizontal expansion.In Section 2 presently preferred embodiment, each band is roller chain, such as, firm from Driving type chain, this chain has hollow pipe rather than solid Chain element.Refractory tube suspension wire passes chain pipe joint, and described End support wiry is in described chain pipe joint.In two embodiments, by the drive system pair being described in detail below Transport element or " carrying " carries out synchronizing to drive.The mobile holding making described band synchronizes can keep carrying the tinsel of refractory tube Parallel to each other and be straight, i.e. orthogonal with the wafer direct of travel along machining path.Applicable alignment roller can be used or lead Lead device.

It is essential that the ultralow mass transport device system of the present invention has a significant advantage, i.e. need not use conveying Device support bar, therefore essentially without covering bottom wafer surface, this just makes higher in travelling speed or that furnace length is shorter situation Under carry out effectively be total to diffusion be possibly realized.

In two embodiments, make wafer sequentially pass through some regions of diffusion furnace, be positioned at simultaneously and be spaced along refractory tube On the annular ledge opened, this causes of reduced contamination.Described bearing can have the configuration of multiple exterior contour, such as, conical, circular (annular), vertical sharp-edged, inclination, bi-conical, square top, fin, the combination etc. of rib and these shapes.Fire proofed wood Material is preferably selected from high-temperature ceramics or vitreous material, and described material can be carried out by casting, dry-pressing, extruding or machining Accurately configuration, and preferably comprise at least one in silicon dioxide (comprising silica glass), aluminium oxide and zirconium oxide.

The configuration in riser region and/or roasting region is unimportant to equipment or the operational approach of the present invention, IR lamp or electricity Resistance heating element heater has multiple arrangement.Such as, in Section 1 embodiment, in the case of the narrow width (delivery system is narrow) of stove, Or in the case of only end face phosphorus doping, HI-IR radiant flux lamp can be used in Zone Full to implement all heating.At this In a little technique application, optionally using HI-IR region, described HI-IR region uses IR lamp isolation module to raise the temperature to Preferably soaking temperature.In other embodiments, the some regions comprising rising (buffering) region and soak zones can be independent IR lamp heated type region.

In Section 2 embodiment, in the case of the processing route width (delivery system is about 1 to 2 meters wide) of stove, or In the technique being doped with boron or being doped front with phosphorus and be doped the back side with boron, (wherein temperature is higher than 950 DEG C, such as, in the range of 1000-1100 DEG C), baking heat element can be resistance radial pattern, such as SiC bar or coil pipe Formula element, described element is optionally housed in protectiveness quartz ampoule or re-radiation (opaque) ceramic mould pipe.

In any one disposition of heating component embodiment, can Hybrid Heating element, i.e. independent IR lamp, HI-IR can be used Radiant flux isolation module and resistance heat radiation/re-radiation element.Such as, input raises (baffle plate) region can be independent IR Lamp, a most optional HI-IR flux isolation module, the high temperature resistant spoke in the followed by second roasting region and soak zones Penetrate/re-radiation element.Soak zones may be only the extension in roasting region.Equally, roasting region is probably buffering or raises The extension in region.That is, the title in region is not determiner, implement to the type of the element above and below delivery system, Position sum purpose selects to be to realize required sintering temperature and machine process (phosphorus diffusion, boron spread or both).

In the low quality delivery system of the present invention, wafer will not encounter band of wire mesh or ceramic roller, but is supported on In ceramic support, therefore there is no metallic pollution, wafer will not be formed focus, and wafer will not be as conventional roller conveyor system System is equally biased to side or opposite side.It addition, the diffusion technique of the present invention is the technique of high-radiation flux driving rather than leads Heat, longer wavelengths of technique.

In Section 1 chip conveying system embodiment, delivery system side band comprises longitudinally evenly spaced drive hole. Each band is configured to Infinite Loop, and described ring includes transporting section (being used for travelling forward, through machining area) and returning section.Logical Crossing one or more pin at the port of export of stove drives roller to carry out described band synchronizing to drive.

Described band is typically resistant to elevated temperatures metal, such as, a member of austenitic nickel-based superalloy series, the most in fact The scheme of executing is nichrome, i.e. the ni cr alloy of 80/20.Other carrying material comprises titanium, (such as 600 types are because of section for Inco nickel Nickel) or other high temperature alloys.Described band slides on every side, stove region in the passage have protection, and passage component is by aoxidizing Aluminum, silicon dioxide, quartz or other high temperature low-frictional force ceramic materials are constituted, so that the heating to described band reduces to minimum.Appoint Selection of land is brought up and is cooled down described band described in the compressed air after surrounding air or cooling being mapped to.

In Section 2 transports embodiment, use roller chain rather than described band, and need not vertical support frame.On the contrary, outstanding Every one end of close plating silk is arranged in the tubular sleeve pivotal parts of side chain link.Each side chain is made pottery at low-frictional force high temperature Groove in ceramic material slide block or passage slide, or straddle on the guiding ridge on described slide block, and serve as conductor, It is used for maintaining the linearity tracking of chain and suitably alignment.By being positioned at the chain wheel drive system below the outlet of diffusion furnace or arrival end (two drive sprockets being spaced laterally apart in same drive shaft) drive described chain.It is positioned at return path in chain wheel drive In the case of below arrival end, to changed course steel free pulley sprocket wheel or have the wheel of flange to be appropriately positioned, obtain tractive and drive Dynamic system.In the front end of stove, the second changed course free pulley being spaced laterally apart makes chain upwards forward on entrance free pulley, and described entrance is empty Runner makes chain changed course return on processing route, thus forms loop.Use suitable changed course free pulley and/or roller, optionally will Described driving be positioned between the arrival end of stove and the port of export Anywhere.Can be in the cooling section of stove and/or returning On footpath, loop, described chain is cooled down, cool down preferably through induction ventilation air or compressed air.

About high intensity IR flux heating element heater embodiment (using in the downstream of buffering and/or riser region), HI-IR district Territory makes temperature quickly (in about 2 seconds) be increased to diffusion technique set point, and described diffusion technique set point is at about 700 DEG C to about 950 DEG C scope in, simultaneously right by the wafer surface scribbling adulterant being irradiated with high intensity short wavelength's IR radiant flux Described surface carries out light regulation, so that diffusion velocity is faster.Compared with long wavelength radiation technique, this embodiment is in diffusion technique In utilize short wavelength's IR radiant flux, this make spread process time shorten half or more, cause production capacity double or Bigger.As an example, in operation, the stove of the present invention can complete diffusion in 6 minutes and process, and the speed of current common process It it is 12 to 14 minutes.Therefore, production capacity is double or bigger.It addition, the resistivity of battery p-n junction layer is not only more equal on wafer Even and be consistent in different chips, and in " optimum " between 45-100 ohm-sq centimetre.

One importance of the quick diffusion technique of the present invention is, is using in the case of IR lamp, described IR lamp be It is essentially higher than under the power of conventional oven and operates (percent of maximum lamp rated power).In Section 1 embodiment, control Device uses algorithm based on experience to adjust in each area and the power of lamp of top and bottom, and described adjustment is According to default temperature required, only carried out by Control of Voltage.In Section 2 embodiment, monitored each by thermocouple The corresponding temperature in region, and the voltage of lamp is adjusted by feedback circuit control algolithm.It addition, monitoring voltage is to guarantee Will not be to the voltage of lamp supply excess in the case of thermocouple lost efficacy.

In conventional static rotating roller stove, lamp operates under the power of 5-20%, and the feature of the most described lamp is: if Do not carry out effective light regulation, then flux is lower and wavelength is longer.

In conventional metal mesh belt stove, subject matter is the metal ion pollution of wafer, this is because the direct position of wafer On wire netting or be positioned on the metal " point " being incorporated in band.Even if employing pottery ball coating, gold on metal mesh belt Belong to ion cloud still to overflow from the net metal of described band, thus the chemical property of solar cell layer is adversely affected. Have been attempted with phosphorus dopant the bottom of wafer is coated, to reduce the metallic pollution from metal mesh belt.But, this leads Cause to be formed p-n junction layer on the bottom of wafer.This needs again extra processing step to etch away described bottom p-n junction layer.Institute Stating etching step and be typically batch processing, this is with the extra time, thus slow down speed of production.

The low quality earthenware delivery system of the present invention processes and solves these problems.First, metal transports assembly (band Or chain) it is placed on the side in stove region, and these assemblies are configured to not radiated [hot] by element, and this extends assembly life-span.The Two, the transverse wire transported protects completely in low quality earthenware, and described earthenware is minimum non-with contacting of wafer Rotary type ceramic support member.The drive belt of protection or chain member is had to combine the wafer support tinsel being carried out protecting by earthenware true Protect the atmosphere of cleaning, so that roasting region is essentially without metal ion pollution.3rd, earthenware generally mass ratio Roller is much lower, although and be non-revolving, but activity, i.e. move in stove and outside stove, do not exist Big static heat quality, big static heat quality needs power reduction.It addition, because earthenware hangs on the metal filament, so If earthenware vertically splits, then earthenware keeps on the metal filament and need not make stove stop immediately to carry out Change.For comparing, in solid roll stove, when roller breakage, it is necessary to make stove stop.Finally, wafer does not contacts with earthenware, Being increased to above earthenware on pottery rib bearing, described bearing is preferably arranged to and only supports wafer in edge.

Contrast with the 5-20% operation power grade of the currently available thermal diffusion furnace of above-mentioned routine, the technique of the present invention Embodiment uses the IR lamp of operation under 40-70% power or greater power, as a result of which it is, the lamp IR in the system of the present invention leads to In quality entity higher, and peak value is maintained in short IR scope (below about 1.4 microns), and IR wavelength peak typically about 1.25 is micro- Rice.The relative flux intensity that process according to the invention is produced by IR lamp is about 4 to 5 times in above-mentioned conventional thermal diffusion furnace greatly. It is enclosed in quartz, pottery or the longitudinal electrical resistance heating element heater stablizing in SiC pipe, it is to avoid two side drawing lines (examples by use Such as, drawing lines 1 and 5) in heat fade.

As it has been described above, the stove of the present invention is raising in certain embodiments or/and have employed HI-IR in HI-IR stove region Lamp module, optionally comprises isolated form module.Described module includes having parallel horizontal (crosscutting with carriage direction) cooling/anti- The dielectric reflective device element of emitter passage, placed in the middle in one or more each in described passage of IR lamp.Described passage is optional Covered by the transmissive window that IR is transparent to selecting property, such as, quartz, Vicor, Pyrex, Robax, other high temp glass, artificial indigo plant Gem etc..High intensity many IR lamp isolation module is arranged to facing with each other and spaced apart, and a module is transported at stove carrier Above system, and a module is optionally below described system, in order to define selected IR lamp heating between described module Formula technique roasting region, module lamp and cooling air duct are opened with described zone isolation.In the case of using described window, described Passage is preferably opened on its opposite end, in order to cooling air-flow enters or/and discharge.By manifold, at least at each passage One end introduces cooling gas, and is discharged by cooling gas at the other end or in the middle of two ends.

Transmittance plate window stops the lamp cooling air/gas of high pressure/high speed enter and disturb process island (to carry silicon wafer Delivery system passes described process island), and allow to use a large amount of cooling gas to maintain lamp quartz and glass/quartz simultaneously Transmittance plate sufficiently cool.By isolation and cooling, the present invention allows IR lamp would generally make the housing deliquescing of lamp and bent (this Can reduction of service life) power grade under operate.

In another embodiment, isolation module includes that the IR lamp separated, described IR lamp are with or without channel reflection device, and And have a Robax type windowpane separated below described lamp, therefore, described window (above and below) by carrier, (carrying is described Wafer) come with the spatial separation of lamp.

This isolation geometry, adds the optional cooling of the IR lamp to the present invention, it is allowed to the power of lamp is from 15-20%'s The Current standards of power density increases to the scope of 40-70% or higher.Situation at the IR lamp using 100 conventional watts/inch Under, this cause raise and HI-IR roasting region in firing rate from about 30 DEG C/sec (conventional oven) be increased to about 80-150 DEG C/ Second.This makes firing rate increase effectively 2 times to 4 times than the speed of conventional oven, without causing lamp to turn down, closing or deform. It addition, the lamp isolation of the present invention/optional cooling system allows to increase the speed of carrier band.This causes yield essence to increase, Or allowing to shorten the length (in the case of yield is identical) of stove, this can reduce the footprint area of stove.

In order in soak zones by high lamp power density maintain high flux to carry out phosphorus diffusion, to realize high speed Processing, removes heat from described region.Cooling air stream direction in soak zones is from top to bottom, in order to suppress microgranule to sink Amass on the top surface of wafer and remove described microgranule.Therefore, with high-quality static state ceramic rotary transfer roller conveyor system (wherein Processing method will not remove heat from machining area) contrast, in the system and technique of the present invention, remove heat, so as to Maintain high power density and allow the IR wafer light regulation of high flux, short wavelength, so that described technique is accelerated.Although heat Remove and seem perverse, but the IR of high flux, short wavelength not only compensate for removing of heat.

The power of heating element heater (either IR lamp or resistance (SiC) radiating element, top or bottom) is carried out solely Stand and adjust or adjust by group, to realize the control of accurate thermograde in each area.Can use based on thermocouple Temperature regulation, voltage type power adjustments or hybrid system, use PID controller as above to realize temperature control System.The power adjustments of lamp is preferably voltage type, because this allows to be easy to maintain stable lamp power, the highest to obtain IR intensity (radiant flux) value and the output of the most constant spectrum.Increase it addition, make lamp run under more power density IR flux, and also provide more preferable spectral region, its peak value is in appropriate location.

About the common diffusion technique of the delivery system utilizing the present invention, exemplary process line is configured as follows: 1) by chip oriented one-tenth basal surface towards upper；2) boron dope agent is coated to wafer towards on upper basal surface and make wafer do Dry；3) wafer is carried out upside-down mounting (such as, with rotary upside-down mounting device) so that the top surface of wafer now faces towards；4) phosphorus is mixed On the miscellaneous dose of top surface being coated to wafer and make wafer be dried；5) wafer after codope is transferred to the diffusion furnace of the present invention In；6) in stove, disposably wafer is carried out concurrent roasting, make wafer cool down and be transmitted to the ARC in downstream, slurry screen printing Brush, dry and metallization operations.Because the low quality delivery system of the present invention is also not apparent from covering the bottom surface of wafer, so bottom surface Obtain suitable roasting, therefore boron diffusion occurs, in order to subsequently form back contact.

Transport crash protection system: as an option of stove, the lower half of stove can possess sagging brake unit molectron, In order to prevent from carrying earthenware and the suspension wire of bearing or the bar excessive sag when losing efficacy, such as, this inefficacy be by Cause in wire breakage or elongate under the effect of stress or heat.In presently preferred embodiment, sagging brake unit group Component includes slider part, such as, selected from the center of quartz ampoule, bar or band, described slider part and carrier transport path Line parallel alignment, described centrage is consistent with the longitudinal centre line of stove heating region.Brake unit slider part and the side of furnace chamber Wall certain distance spaced inward, this distance make described brake unit slider part align with the travel path of bearing and Described travel path is spaced below.The end longitudinally in each of brake unit slider part is arranged on (such as) stove roasting region In transverse wall, so, the top of slider part is in the over top of transverse wall.Therefore, if transporting tinsel and pipe molectron Sagging, during this time, bearing can contact with slider part, along with the carrying out transported slides along slider part, and jumps out The transverse wall of stove, without sagging and fracture, or additionally damages delivery system.Such as, the top of brake unit slider part with Interval between the bottom of bearing is about 1 to 2 centimetres.It addition, because of brake unit slider part with bearing path alignedly Spaced apart, so brake unit slider part will not cover wafer, but separate with the side of wafer.

The sidewall heating of outside drawing lines:

In currently preferred heating system, top heating region uses transversal orientation Formulas I R lamp, and adds in bottom Thermal region uses the combination of IR lamp and resistance heating.In order to improve the Transverse Heated uniformity crossing over stove width, resistance is added Hot device is placed on and two longitudinal side wall adjacents, described sidewall be oriented to be parallel with stove centrage and with described centrage every Open, and IR lamp is laterally placed on above or below longitudinal side wall stratie, be preferably lower section.Longitudinal side wall resistance heats Device is arranged in quartz ampoule, earthenware or stablizes in SiC pipe, and described pipe is arranged in below carrier.At 5 drawing lines or broader In stove, described heater is in suitable diffusion temperature in order to keep the wafer in the drawing lines 1 and 5 adjacent with corresponding sidewall. This is particularly suited for common diffusion processing.

Side-wall heater in order to repair and the furnace temperature of sidewall adjacent, this is because, for preventing from making lamp burn, IR lamp adds Thermal element does not the most arrive sidewall and just terminates.If IR lamp heating element heater extends in lateral wall insulation thing, then insulant can be led The local temperature causing lamp exceedes safety operation value.Resistor-type longitudinal side wall heater will not be sent out as main transversal I R lamp Light, but under lower-wattage grade, operate to adjust the temperature in adjacent sidewalls region, i.e. lip temperature, make described temperature foot Enough height, to compensate at the power of lamp end loss and through lateral wall insulation thing to any loss outside stove.

Due to the operation of lower-wattage, described longitudinal heater can be placed on above the horizontal plane of main IR lamp and close Sidewall, typically about 1 to 5 centimetres of interval.In the case of diffusion furnace uses the low quality delivery system of the present invention, described longitudinal direction Heater also can be placed on below the summary of carrier plane, about low than the horizontal plane of earthenware 1 to 3 centimetres, described earthenware bag Include chip conveying support component.

Exemplary sidewall heating element heater includes that coil pipe stratie, described coil pipe stratie are enclosed in because of section In nickel sheath and by MgO powder and described jacket insulation.Being inserted by described element subsequently may be transparent, translucent or impermeable In bright quartz ampoule；Because described element perhaps without in the visible spectrum or neighbouring " luminous " (this depends on required output Power), so carrier pipe transparency is unimportant.It addition, the important safety using carrier pipe to be provided is characterised by, institute State pipe and serve as electricity guard shield or insulator in order to avoid getting an electric shock.Can use other kinds of heating element heater as longitudinal side wall heating element heater, Described element comprises the simple nichrome tinsel air-coil that the power being incorporated in carrier pipe is 1 to 3 kilowatts.Can lead to Cross standard SCR controller to control described sidewall heating element heater.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of the Section 1 embodiment of the diffusion furnace of the present invention, with side view depict inlet transforms region, Baffle area is or/and riser region, optional roasting region, at least one soak zones, cooled region and low quality transmission System；

Fig. 2 is the isometric view of the low quality delivery system (transporting for banding pattern in this embodiment) of the present invention, described Delivery system is arranged in some heating regions of diffusion furnace, and wherein the front arrival end of stove also depicts at oxygen in right side, figure Change aluminum and prop up the wafer on stay tube；

Fig. 3 A is that the band in Fig. 2 transports embodiment equidistantly putting in inlet baffle region and optional HI-IR lamp region Big view, show through the transport to two exemplary wafer of the described stove；

Fig. 3 B is the bottom isometric view of compresses lower section, show the exhaust manifold for soak zones；

Fig. 4 A is the amplification isometric view that the band decomposing out from Fig. 3 A transports, and is used for illustrating details；

Fig. 4 B is equidistantly to regard for the rack assembly of band transport embodiment and the amplification of bent wire Tip retainer Figure；

Fig. 5 is the schematic side view of the stove of the present invention, and lower section is the temperature formed in the respective regions figure to the time Profile；

Fig. 6 has been described with reference to FIG. the key that spectrum output is the speed of IR lamp heated type diffusion technique, and wherein Fig. 6 A is with relatively Intensity against wavelength illustrate the low quality delivery system of the present invention spectrum output, and Fig. 6 B with identical relative intensity to wavelength Illustrate the contrastive spectrum output of high-quality solid ceramic roller system；

Fig. 7 is the schematic diagram of the Section 2 embodiment of the diffusion furnace of the present invention, show some machining areas and chain drives Formula chip conveying system；

Fig. 8 is the equidistant zoomed-in view of the chain delivery system in stove machining area, show two exemplary wafer and passes The transport of described stove；

Fig. 9 is the amplification isometric view that chain drives details, show suspension wire and how earthenware is arranged on hollow In chain pipe；

Figure 10 A is the vertical cross section of the line 10A/B-10A/B through Fig. 9, show the slider plate driven for chain and leads The Section 1 embodiment of lead device, is passage in this embodiment；

Figure 10 B is the vertical cross section of the line 10A/B-10A/B through Fig. 9, show the slider plate driven for chain and leads The Section 2 embodiment of lead device, is rib in this embodiment；

Figure 11 A is the vertical cross section through suspension wire and alumina tube, and the Section 3 showing wafer support is real Execute example；

Figure 11 B is the vertical cross section through suspension wire and alumina tube, show the 4th of wafer support configuration the Item embodiment；

Figure 12 A is horizontal front view, show sagging brake unit slider part relative to transporting earthenware, bearing and gold Belong to locus and the arrangement of silk molectron；

Figure 12 B is the isometric view of the diffusion furnace bottom section of the present invention, and described diffusion furnace bottom section is equipped with a pair Sagging brake unit slide block；

Figure 13 is that this diffusion altogether is for making boron and phosphorus be diffused into the schematic diagram of the process production line in wafer altogether Silicon wafer is processed into the part of solaode；

Figure 14 is to use the conveyor system of the present invention and use longitudinal side wall resistance to add in the action of soak zones bottom The level schematic diagram of the stove of hot device；

Figure 15 is that the replacement of the stove of the present invention using longitudinal side wall heater in top with lower area is schematically real Execute example；And

Figure 16 is the isometric view of the furnace system of the present invention, show in exemplary soak zones and is heated by longitudinal side wall Device is placed on above IR lamp.

Detailed description of the invention

The following specifically describes and illustrate the present invention as an example rather than as to the scope of the present invention, equivalent or former The restriction of reason.This description will clearly enable those skilled in the art carry out and use the present invention, and describes this Bright some embodiments, adaptation form, version, alternative form and purposes, wherein comprises and is presently believed to be business in fact Execute the situation of scheme.

Fig. 1 is the schematic diagram of the diffusion furnace 10 of the present invention, and diffusion furnace 10 includes framework and shell 12, and it has compresses lower section 14 and top section 16, the linear brake lifters that framework 12 is optionally configured with separating along outside (sees Fig. 2 and Tu 3), it is used for making top section 16 raise relative to compresses lower section, in order to allow lamp/subassembly and delivery system are keeped in repair.Stove 10 include following multiple section or region, from entrance or front end 18(in this drawing, left side) hold 20 to outlet or rear (downstream) (right side), is followed successively by:

IT, i.e. from the entrance transmission ends 18 of the adulterant applicator unit (not shown) of upstream；

B-1, i.e. inlet baffle region, it uses one or more compressed air cutter molectron 22；B-l region is optionally Including riser region, one or more heating element heater (not shown) is contained in riser region, is used for making chip temperature from ambient temperature It is increased to about 500 DEG C；

FZ, i.e. initial calcination region, is used for making chip temperature be increased to diffusion temperature, and diffusion temperature arrives at about 900 DEG C In the scope of about 1100 DEG C, what this depended on being spread is phosphorus, boron or both；FZ can be further subdivided into two or two Area above, such as；

HI-IR region, i.e. high intensity IR lamp array, preferably top are or/and lower isolation reflectoscope molectron 24- U, 24-L, for obtaining the temperature being up to about 950 DEG C, followed by；

HTZ, i.e. high-temperature area, heats it with resistance radiation (SiC) element 27, for obtaining up to 1100 DEG C temperature, what this depended on being spread is phosphorus, boron or both；

S, i.e. soak zones, has the upper and lower IR lamp or resistive element 26-U, 26-L separated；

B-2, i.e. outlet damper region, has air knife molectron 22；

C, i.e. cooled region, does not the most have resistive element or IR lamp；And

OT, i.e. outlet delivery region, for being transferred to the wafer after diffusion roasting for carrying out adding of silk screen printing Construction equipment, described process equipment on front silk screen printing colelctor electrode finger piece and bus and on the back side the silk screen printing back of the body connect Contact layer (not shown), then carries out roasting to form ohmic contact.Outlet delivery region optionally comprises (right with outlet of still Side) adjacent top is or/and lower air cutter molectron.

The upstream and downstream of the stove of the present invention is low temperature transmission belt 28-U(upstream) and 28-D(downstream), described band is connected to Anti-reflecting layer applicator, screen process press, followed by metallize stove.The stove of these low temperature transmission belts 28-U and 28-D and the present invention The drive system 30 of 10 connects.

In Section 1 embodiment, the low quality drive system 30 of the stove of the present invention includes: pin drives roller 32(by being arranged in Motor 34 that the outlet (right) of stove is held and chain or band 36 driving), chip conveying band molectron 38, a dummy roll 40 and comprise The tension system 44 of power roller 42.Tension system 44 comprises the automatic tension compensator spring serving as buffer, is used for helping prevent Get loose.It should be noted that and drive geometry by this, haul band 38 along feed path F through regional from left to right.

The stove of the present invention comprises: multiple high-tension rooms, which defines the intra-zone of shell 12；And multiple air manifold, It comprises entrance and air vent, is used for making environment or forced air stream enter regional, such as arrow I(entrance) and E(aerofluxus Mouthful) shown in, in order in each region, maintain suitable temperature.It addition, at isolation lamp/subassembly 24-U and 24-L(in the feelings used Under condition) reflector body passage in provide forced air so that be arranged in described passage lamp cooling.High-intensity lamp group The surface of each in component 24-U and 24-L is covered by a piece of suprasil, in order to seal reflector passage so that it is with The wafer just accepting light regulation in HI-IR region separates.The cooling of this lamp allows lamp under the peak power of about 60% to 100% Running, this is far above being currently available that competitive unit.This provides heat immediately to wafer and raises and the irradiation of high intensity IR, from ring Border temperature is increased to the peak value diffusion regulation temperature of 700 DEG C to 950 DEG C (phosphorus diffusions), and provides high-strength light regulation.

The yardstick of Fig. 1 makes to illustrate solid thermal insulant 46 in each position, but those skilled in the art It will be appreciated that shell comprises the insulant configuration block of necessity.Optionally provided air inversion in insulant entrance region (being illustrated by arrow 48), described air inversion is contrary with hot-fluid.Air when entering from insulant extract heat and make hot recirculation In region, this is the heat exchange operation that efficiency is the highest.It should be noted that and be schematically shown as interlocking by lamp 26-U and 26-L or resistive element 27 , in order to provide uniform heating and/or IR photon field；Optionally it is arranged to not hand over by lamp 26-U and 26-L or resistive element 27 Wrong.

Turning now to low quality delivery system 30, Fig. 2 isometric view illustrates stove 12, wherein removes exterior panel with exhausted Edge thing is to illustrate the framework of compresses lower section 14, and described compresses lower section 14 has arrival end 18(lower right) and a port of export 20(left side Top).For the sake of clarity, entrance and exit transmission belt 28-U and 28-D are not illustrated.Four angles of the siding track 52 of stove are painted Bracket and lifter 50 are shown；These brackets and lifter 50 are in order to show from compresses lower section 14(figure) promote top section 16 (not shown) to carry out part (such as, lamp, stratie, delivery system element etc.) checks, adjusts, safeguards With repairing/replacing.Compresses lower section 14 comprises siding track 52, lateral wall insulation block 46-S and insulant interior zone segmentation block 54.For The not details of mictium 38, do not illustrate the collets in front, and described collets are positioned at the front end of baffle area B-1 and by B-1 Separated with high intensity IR region HI-IR, and it is positioned at the rear end of cooled region C.

Collets 56 form the bottom in some regions.These bottom collets 56 generally have aperture, are slit 88 herein, this Some holes mouth allows to extract out the waste gas of heat with ID fan (not shown) plus the high-tension room (not shown) below bottom.This is empty Air-flow removes heat from regional, thus allows the operation of element (lamp, SiC bar or coil pipe) to produce higher output, and also Allow to extract pollutant out, because air stream is from top to bottom.This hot gas/air flow pattern causes the pollutant in stove region Level reduces, and therefore causes product cleaner.

Depicting aperture 58 in siding track 52 in the presence of and the lateral wall insulation block 46-S of far-end, described aperture 58 is for pacifying Dress resistive element 27 is or/and high intensity fluorescent tube 26(for clarity sake, only depicts in every kind of element) and for even Connect electric lead, the described element/lamp width across stove region.Delivery air chamber 60 for high intensity IR lamp region, bottom 24-L Supplied compressed air in the ring between reflector passage and lamp by circuit 62, and be discharged to outside in lower section on demand, Or be discharged in adjacent downstream soak zones.

For clarity sake, a part for low quality active transmission band system 30 is only depicted at right-hand member.Side band 38 and driving Pin rodent in the dummy roll 40 separated of system 30 closes.Inside cooled region C, only can see that dummy roll 40 and under it The driving roller 32 of side.Depicting two wafer W-l and W-2 at arrival end (right side), described wafer is placed on lateral oxidation aluminum pipe 64 On, it is positioned on the position being transmitted through stove.

Fig. 3 A is the amplification isometric view of the arrival end 18 of the stove 10 of Fig. 2, show two wafer W-l's and W-2 of carrying A part with delivery system 30.Two bands separated 38 of delivery system 30 are arranged in U 66, described U In 66 tops being formed at left and right lateral wall insulation block 46-S.Each band comprises the hole 68 accurately separated, described hole 68 and idle running The pin 90 of roller 40 engages.The support 70 erect separates regularly also along described band, described support 70 bearing metal silk 72, pottery Porcelain tube 64 is placed on described tinsel 72.Such exemplary metals silk is a diameter of 0.080 " nichrome.Bearing 84(is real at this Execute in example, herein for ring) it is arranged on, is arranged on pipe 64, or be formed in pipe 64, and be spaced laterally apart along described pipe.? During transporting through stove 10, wafer is positioned in seat rings, so, and connecing between wafer back surface and transport molectron element Touch seldom, see the footprint area 96 in Fig. 4 A.

In the case of pipe 64 ruptures or splits, tinsel 72 can keep pipe 64, until pipe 64 can be changed.Due in band Hole 68 and roller (driving roller and dummy roll) in pin 90 demarcate, the support of each band is moved by the relation of parallel alignment, therefore Alumina tube keeps crosscutting with wafer supply direct of travel (as shown by arrow F).

Fig. 3 B is the lower section isometric view of the compresses lower section 12 of stove, for clarity sake, removes framework.Bottom collets 56 Across side frame 52, described bottom collets 56 have air vent channels 88(Fig. 3 A and can find out).Steel plate 100 and the end of collets 56 Portion is spaced apart, and this is spaced apart hot-air and provides catcher high-tension room.Exhaust manifold molectron 102 is by transverse tube 106 Collar 104 on end is connected to described high-tension room (spaces between 56 and 100).The other end of transverse tube is connected to collection tube Road 108, described pipeline 108 gives off hot gas from exhaustor or flue tube 110.

Fig. 4 A isometric view depicts low quality delivery system 30, and U molectron 74, this embodiment Band 38 moves in described U molectron 74.Fig. 4 B is the feature of the single-side stand molectron of Fig. 4 A.

Each band 38 is supported on quartz slider part 74, and the cross section of described slider part 74 is U-shaped and has relatively Short vertical sidewall.With high-temperature ceramics clay, pair of holders tape member 76 is adhered on the top of U-shaped arm, described keeper Tape member 76 is made up of quartz, aluminium oxide or other high temperature fiber type ceramic materials, is so fully overlapped to will pass through thing Reason means hold the tape in passage and protect described band so that it is will not touch heating element heater, thus keep the described band to be Cold.Optionally use environment compression surrounding air that described band is cooled down.

Support 70 comprises the vertical leg 80 being fastened on vertical protuberance 78, and described protuberance 78 is by bringing into from described Eleven punch 11 92 is formed.Lower limb 80 and protuberance 78 can be tightened together by any appropriate ways, such as, by spot welding, lead to The protuberance crossing alignment carries out riveting or fastening with screw with leg holes 94.The upper end of rack leg 80 with one or more auricle 82, Each auricle has a hole, refractory metal silk or bar 72 to be inserted in described hole.Alumina tube 64 is sliding on described tinsel Move and carried by described tinsel.Each pipe optionally comprises multiple support part 84 being spaced laterally apart, and is ring herein, wafer It is positioned on support part 84, as shown in the footprint area 96 in Fig. 4 A.

Seat rings 84 can have multiple cross-sectional configuration, and scope is: simple flat surfaces annulus (as shown in Figure 4 A) To gradual shrinkage profile, such as, cross-sectional profiles is the profile of bell shaped curve shape.Various profiles see Figure 10 A, Figure 10 B, Figure 11 A With Figure 11 B.It should be noted that in figure 4b, the bent tip 86 of tinsel 72 is contained between two auricles, thus locks tinsel, To prevent transverse shifting wiry, this transverse shifting can cause the other end (right side) to fall down from the auricle of right side support Come.It should be noted that in Figure 4 A, right side wiry has extended substantially through the outside auricle of the support of its correspondence.Use has The tinsel of free end can allow wire length to expand and shorten, without falling down in the hole from auricle.

The band of the delivery system of the present invention and the key character of chain embodiment are its ultralow quality, easily installation, hold Easily keep cleaning, when transporting wafer through stove, the contact point on wafer is little, and easily safeguards.As shown in Figure 4 A, because of For there being so many tinsels being sufficiently close spaced to provide for wafer to support, so the pipe of breakage and/or tinsel are usual Can remain to be replaced when the shut-down mapped out because lose one pipe or tinsel will not have a strong impact on production energy Power.

In the stove embodiment of the present invention, in the range of heating the wafer to diffusion temperature (in several seconds) as quick as thought or close Diffusion temperature scope, in the embodiment described in which, is using high-strength with the entrance adjacent or downstream of the stove immediately preceding the present invention Degree IR lamp or isolation module.By high intensity short wavelength's IR emittance, wafer being carried out light regulation, described emittance is about mesh 4 to 5 times of preliminary roller stove greatly or bigger, therefore spreads the speed carried out faster.As an example, in the stove of the present invention, temperature Diffusion temperature is reached in several seconds.The more important thing is, by using isolation module in HI-IR region, and due to can be Giving described HI-IR region and soak zones power elements under high voltage, the IR flux in technical process is higher, and few Completing diffusion in 6 to 8 minutes, this time span is 1st/to three/2nds of current system.

Fig. 5 and Fig. 6 illustrates these principles.The upper part side view of Fig. 5 schematically depicts the stove of the present invention, lower section It it is the temperature formed in the respective regions graph outline to the time；Imaginary curve P is only enterprising in front by the heating of IR lamp When the diffusion of row phosphorus is to form p-n junction layer, the temperature profile in the stove of the present invention.Solid-line curve shows, in the stove of the present invention in order to The carrying out temperature and to exceed about 200 DEG C of the boron diffusion forming back contact and carry out, and need (such as to be taken off with resistive element The SiC bar shown) at least some region is heated.It should be noted that pole produced by the IR lamp of the stove of the present invention or resistive element Steep profile, this can make wafer be rapidly achieved the technological temperature that phosphorus (and/or boron) spreads.Use commercially can buying of IR lamp heating To contrastive solid ceramic roller stove show and generally follow the phosphorus diffusion profile of dotted outline, figure is designated as " P.A. " (prior art).Because roller has been hot in stove, so being automatically adjusted to run at lower power by lamp (see figure 6B, lower section), therefore cause temperature profile slope substantially and significant lower, and the time reaching temperature is longer, has grown the most several Minute.The most important aspect of curve chart of this Fig. 5 is, when using the stove of the present invention, completes the speed of diffusion substantially Faster (point " D terminal " on vertical coordinate), wafer proceeds cooling and is transferred to the silk screen printing (point on vertical coordinate " XFER ").

For comparing, contrastive prior art phosphoric diffusion technology (dotted line in Fig. 5) lower-wattage set under continue into Row soaking, the time is much longer, as shown in point to the arrow on the right side on described dotted line.The high intensity IR radiant flux phosphorus of the present invention expands The day labor skill usual used time is 1/2 to the 1/3 of conventional conduction of heat process time.Therefore, production capacity is the highest, and with phase Compare Deng the conventional oven (400 " long are multiplied by 36 " are wide) of output, furnace volume much smaller (length is less than 300 ", and width is one Half).

Fig. 6 A and Fig. 6 B has been described with reference to FIG. spectrum output to be in light regulation, raises and improve in HI-IR region IR diffusion work The key of skill speed.The spectrum output of lamp changes with the power of lamp, can be expressed as the percent of the maximum power capabilities of lamp. Fig. 6 A relative intensity illustrates the spectrum curve of output of the low quality delivery system of the present invention to wavelength.Upper curve is theoretical Maximum of T, depicts IR peak value and is about 1.2 microns and relative intensity is about 12.5.It should be noted that visible spectrum VS in left side, Illustrate with dotted line.The lower curve being designated as " present invention " shows, the ultralow quality in the present invention using HI-IR lamp module is transported In system, modulating voltage control system can be used to operate IR lamp under about 40-100% rated maximum (shown here as about 40-70%), And the maximum of intensity at peak value is 8.

For comparing, Fig. 6 B illustrates the contrastive of high-quality solid ceramic roller system with identical relative intensity to wavelength Spectrum exports.In this contradistinction system run together with Monitoring and Controlling feedback system hot with thermocouple type, lamp must be about 20% Power under run.But, relative intensity exponentially reduces, and the peak value under the peak strength of about 1.8, being designated as " PA " moves Position is to closer to 1.75 microns, and this radiant flux is less than 1/4th of the technique of the present invention.In conventional system, it is displaced to Longer wavelength, lower energy spectrum profile are the most critically important.

Therefore, in the system of the present invention, lamp can operate under greater power, thus causes relative intensity to increase to 4 to 5 Times.Wafer is adjusted by the IR intensity of this increase being applied to quickly on wafer, to promote phosphorus or/and boron expands quickly It is scattered in advanced wafer material, thus forms corresponding knot and back contact.Therefore, in the system of the present invention, IR intensity is more Height and long enough of holding time, in order to process faster.

Fig. 7 to Figure 10 B relates to the Section 2 embodiment of the ultralow quality delivery system of the present invention, and this embodiment uses one Suspended from described chain to the chain separated, wafer support tinsel and earthenware.In Fig. 7, the description carried out Fig. 1 above is fitted For numbering identical part.It should be noted that IT and B1 region is combined into riser region in this embodiment, in described rising district Territory makes chip temperature be increased to about 500 DEG C to 900 DEG C from room temperature, comprise the situation of HI-IR isolation lamp module in riser region Under be 900 DEG C.Being roasting region after this, described roasting region raises the temperature to spread processing temperature about 950-1100 DEG C, what this depended on being spread is phosphorus or boron, or both.As it can be seen, the exemplary resistance disclosed in the employing of roasting region SiC element.In soak zones, keep roasting set point temperatures, for preventing from making figure chaotic, do not illustrate heating element heater, but refer to Fig. 1 and Fig. 5.As it can be seen, cooled region is divided into two sub regions CZ-1 and CZ-2, but CZ-2 can be in outside.

In figures 7 and 8, transported by roller chain 112, motor 34 provide the sprocket wheel 114 of power to make roller chain 112 Mobile, described motor 34 is positioned at below the port of export of stove 20.Free pulley (be in this case sprocket wheel or flanged take turns) 40A-40C is arranged in entrance, exit and the upstream of return path R, in order to make the chain in shown driving ring change direction.Arrange Spring offset tension force in driver 30 downstream and free pulley system 44 provide suitable tension force.It is provided with deflector roll along chain link 116 and slideway block 74, in order to maintain described path to be straight.Air knife 22 is in cooled region or cooled region is outer to described chain Cooling compressed air is provided.It addition, pipe cooler 118 can be arranged in returning section, it is used for carrying out the coldest to described chain But.

Fig. 8 show on the left of two chain 112-L(separated) and 112-R(on the right side of) how to be supported on the groove in slide block 74 Or in passage 120.The transverse wire 72 supporting earthenware 64 has end 122, and described end 122 is through tubulose chain link sleeve pipe 124.Tinsel 72 separates about 1 " (2.5 centimetres).

Fig. 9 is to show the enlarged drawing that the alternately chain link of tinsel 72 is installed.Middle chain link has solid pintle 126.It is covered with in chain link roller 128(Fig. 9 not showing on chain link sleeve pipe 124 and pintle 126；It is shown in Figure 10 A and Figure 10 B) gold The free end 122 belonging to silk ends in push type or screw-type nut or other kinds of securing member 130,140, described to prevent Tinsel falls down (seeing Figure 10 A, 10B) from sleeve pipe 124.

Figure 10 A and Figure 10 B illustrates two embodiments of slider plate 74.In Figure 10 A, slider plate comprises groove or passage 120, Chain 112 is supported in described groove or passage 120.The free end 122 of tinsel 72 has screw thread, is used for receiving lock nut 130. Show optional space washer 132.It is peripheral that bearing 84 has inverted V-shaped, and therefore wafer support is in circumferential ridge 134.Figure 10 B In, slider plate 74 comprises the ridge 136 can with various configurations, and described configuration comprises linear type or shaped form (inclination) sidewall. The side chain link of chain 112 straddles on ridge 136 and is guided by ridge 136.In this embodiment, slider plate 74 does not generally have Outer lateral mass 138, described plate is smooth on the both sides of described ridge, as shown in define the dotted line of side block 138.It addition, it is golden The tip 122 belonging to silk 72 ends in cap-type or push type nut 140.In this embodiment, the profile of bearing is gradual shrinkage top, horizontal Cross section is half-sine wave.

Figure 11 A and Figure 11 B show two further embodiments of bearing 84, and Figure 11 A show asymmetric fin-shaped and props up Seat, described bearing has the outer surface (right side of ridge 134) of inclination and side surface that is vertical or that tilt.Figure 11 B show and props up The embodiment of the current preferably form of seat, i.e. both sides gradual shrinkage cone, optionally has circumferential rib 134 at apex, and two gradually Contracting side is converged at described apex.Wafer product is all provided and supports by described rib or long inclined-plane, as respectively by wafer W-1 and Shown in the position of W-2, this depends on that the bearing 84 interval along pipe 64 is compared to the width of (wafer) product.Such as fruit product very Greatly, then basal surface is positioned on described rib, (referring further to 96 in Fig. 4 A) as shown in wafer W-l, and as fruit product does not has wafer Shown in W-2 the widest, then the only outside lower edge of product is positioned on inclined-plane (as shown in the figure).This bearing is to be bonded at earthenware 64 Upper rather than integral part of.The vertical height of bearing optionally changes, in order to adapt to various transport and stove design and Configuration.

Figure 12 A and Figure 12 B illustrates optional transport crash protection system, and described system includes being arranged in side by side bearing Sagging brake unit below travel path.Figure 12 A show the sagging brake unit slider part 144 transported below molectron Locus and arrangement, described transport molectron includes driving chain 112, earthenware 64, bearing 84 and tinsel 72.

As shown in figure 12a, sagging brake unit molectron 144 is in order to prevent from carrying the outstanding of earthenware 64 and bearing 84 Close plating silk or bar 72 excessive sag when losing efficacy, such as, this inefficacy is owing to tinsel breaks under the effect of stress or heat Split or elongate and cause.In exemplary embodiment, sagging brake unit includes slider part 144, such as, selected from quartz Pipe, bar or band, described slider part 144 aligns with the centerline parallel of the carrier transport path shown in arrow F, described in Heart line is consistent with the longitudinal centre line in stove roasting region.Brake unit slider part 144 with the sidewall of furnace chamber spaced inward certain Individual distance, this distance makes described brake unit slider part 144 align with the travel path of selected bearing and at described row Inbound path is spaced below.Holding longitudinally in each in the transverse wall 54 being arranged on stove roasting region 23 of brake unit slider part In recess 146, so, the top of slider part is spaced apart in the over top of transverse wall 54.Therefore, if transport tinsel and Pipe molectron is sagging, and during this time, bearing 84 can contact with slider part, along with the carrying out transported is sliding along slider part Move, and skip the transverse wall of stove, without sagging and fracture, or additionally damage delivery system.Such as, brake unit slide section Interval between top and the bottom of bearing 134 of part 144 is about 1 to 2 centimetres.It addition, because brake unit slider part The most spaced apart with bearing path, thus brake unit slider part will not cover wafer (see Figure 11 B wafer W-1 and W-2), but separate with the side of wafer.

Figure 12 A also shows, above each conveyer chain slider plate 74 in its insulative sidewall block 46S, on lower section or side Be provided with compressed air hose 148, be used for providing to the bottom of slide block 74 cooling air and by the hole 150 in slider plate 74 to Chain 112 is driven to provide cooling air.

Figure 12 B show the bottom section 14 of the exemplary diffusion furnace 10 that width is 5 drawing lines, and described bottom section 14 is joined Have a pair sagging brake unit slide block 144, each sagging brake unit slide block 144 and a series of bearing 84 side-by-side registration and Described bearing 84 is spaced below.Lateral clearance protective plate 152 can be placed, to alter course in transport across the width of stove at arrival end Arrive the most again when Horizontal production transports horizontal plane and guarantee any sagging gap wiry.

Figure 13 show process production line 154, and it includes the first doping device equipment Do-1, uses boron doped compositions The basal surface of the silicon wafer of preparation is doped by (arrow B).Wafer is doped with boron by Do-1 and makes wafer be dried After, upside-down mounting device 158 inverts described wafer so that the top surface of wafer is towards upper.Then by supine for the top after reversion Wafer is transferred to the second doping device equipment Do-2, phosphorus doping compositions (arrow P) is coated with in this doping device equipment Do-2 On the top surface of wafer and make wafer be dried.Then the wafer after having carried out double application with boron/phosphorus is transferred to the present invention Diffusion furnace 10, carry out such as common diffusion roasting the most mentioned above, cool down in the cooling section of stove, and transmit To ARC device A RC 158, in ARC device A RC 158, sunk by plasma enhanced chemical gas phase Amass and coat ARC, such as SiN3.After coating ARC, wafer is transferred to printing station, in printing station, printer/ Silver-based paste " ink " is coated to the top table after p-doped/diffusion with the form of the fine circuit separated by exsiccator equipment 160 (the most when needed, back contact aluminum based sizing is coated on the basal surface after boron-doping/diffusion on face；Boron-doping basal surface is usual Need not aluminum base back contact slurry).Then " after printing " wafer is transferred to exsiccator 162, and exsiccator 162 is being less than Burn the organic bond in slurry under about 600-650 DEG C fixed temperature, as it can be seen, give off VOC at 164, then make to give up Gas condenses out or burnouts in thermal oxidizer.It is transferred to metallize in stove 166 by the wafer after printing, at metallization stove In 166, wafer is carried out roasting so that selective back contacts slurry flows in pantostrat, and on front, form ohm collection The fine grid of electrode, described grid is fired in p-n junction layer, but is not passed through p-n junction layer.The battery 168 of gained proceeds Each cleaning, deburring and testing procedure, then form band and be assembled into array, in order to lamination has become between each glassy layer Solar panel.

Figure 14 to Figure 16 illustrates to use longitudinal side wall heater to improve in regional (mainly soak zones) Heating horizontal homogeneity so that the sidewall near stove corresponding drawing lines (such as, in the stove that width is 5 drawing lines, line Road 1 and 5) in the wafer that transported be in processing temperature, this temperature is uniform on its width.To identical in Fig. 1 with Fig. 7 The description in part and region is applicable to Figure 15.In this embodiment, stove region is riser region 19, the most multiple soaking zones Territory S 1, S2 ... Sn, followed by least one cooled region CZ, such as C1 are or/and C2.Lamp 26U and 26L in described region High IR flux is provided to be adjusted and heat.19(upper and lower, riser region is 19U and 19L respectively) make wafer from environment Temperature rises rapidly in about 500 DEG C to 700 DEG C or higher scope.First soak zones S1 make wafer front and back, End face and bottom surface are increased to required diffusion temperature, and described diffusion temperature is at about 950 DEG C (only phosphorus dopings) Dao about 1100 DEG C (phosphorus Codope with boron) in the range of.Set point temperatures is processed in diffusion needed for remaining soak zones S2-Sn keeps.Then exist Wafer is cooled down by one or more cooled region C1, C2 etc..In this embodiment, in the lower half of region S1, S2, And in the C1 of region (when region C1 by soak zones Sn replaced time, Sn is S3 in this embodiment), above lamp Arrange side-wall heater 170.

Figure 15 show and uses side-wall heater 170U and 170L in top with lower area.In this embodiment, Side-wall heater 170L is used in riser region, bottom.Heater is used in shown all soak zones.

Figure 16 show 3 line tunnel-types, and described stove carries wafer W-1, W-2 and W-3 in the directionf.Remaining parts is numbered Identical with Fig. 3 A.In soak zones, be respectively used to two side-wall heater 170R, 170L of right and left sidewall be shown as with Its sidewall 46R and 46L is adjacent and above transverse lower portion lamp 26L.Described side-wall heater may optionally extend into rising district In territory 19 or optionally roasting region.Described side-wall heater is placed on has, from corresponding sidewall 46R, 46L, the distance 172 being pre-selected Place, the scope of described distance 172 is about 1 centimetre to about 5 centimetres.Described side-wall heater may be supported on transverse area segmentation block 54 In in the recess 173 that cuts out, or be supported in the through hole (not shown) in described piece.As it can be seen, described sidewall adds Hot device includes that outer quartz tube 174, bar or coiled resistive element ITS are placed in described outer quartz tube 174.These sidewalls add Hot device guarantee the outer rim (near the edge of sidewall 46R and 46L) of the wafer W-l in drawing lines 1 and the wafer W-3 in drawing lines 3 by Individual border land is uniformly heated.

The diffusion furnace of the present invention of subject application is widely used in solaode manufacturing industry, i.e. be applicable to following work Skill step: solar cell wafer is carried out roasting so that phosphorus is or/and boron spreads and is diffused in wafer substrate altogether, thus shape Become p-n junction layer or conductivity back surface layer.Described system is clearly the improvement to currently available stove, thus provides higher Production capacity, this be due to: process time is the most shorter, it is less to cover, energy requirement is lower, the process contamination of wafer more Few, and the uniformity in p-n junction layer and boron-doping back surface layer improves to some extent.Therefore, the system of the present invention obviously the most likely by It is used as the new standard making adulterant be diffused into the equipment in solaode advanced material wafer and method.

Parts list (this parts list be to examine for convenience and provide and can enter in the case of being allowed Row is deleted)

Claims (10)

1., for processing a continuous conveyor diffusion furnace for solar cell wafer, described diffusion furnace is with exercisable combination shape Formula includes:

A) multiple heating and cooled region, described region is to orient by the order of stove entrance to outlet of still,

I) described region is arranged by syntopy, in order to by described region deviding continuous print longitudinally processing carrier road Footpath, described path is oriented in less horizontal plane, and each in described region comprises the lateral wall separated, processome Amassing and be defined between described lateral wall, described processing volume is along the horizontal plane being substantially parallel to described machining path plane It is divided into region top half and the latter half, region；

Ii) described heating region comprises selected from IR lamp and the heating element heater of resistance radiating element, described heating element heater be oriented with Described longitudinally processing conveyor path is crosscutting, in order to heat described processing volume；

Iii), during the heating element heater of described transversal orientation is arranged at least some of described heating region, it is positioned at described region upper half In at least one in part and the latter half, described region；

Iv) at least one pair of resistance radiant heater element, described resistance radiant heater element be arranged in the latter half, described region or/ With at least one in top half, described resistance radiant heater element is oriented to be parallel with described longitudinally processing carrier road Footpath, of each centering is arranged to adjacent with in described lateral wall；

B) low quality conveyor system, is used for receiving solar cell wafer and making solar cell wafer add along described longitudinal direction Work conveyor path moves to described outlet of still from described stove entrance through described region, and described conveyor system includes:

I) multiple refractory metal silks separated, described tinsel is oriented crosscutting with described longitudinally processing conveyor path, institute State length wiry between the described sidewall of described conveyor system, define the useful wafer fortune through described stove region Send width；

Ii) refractory tube of non-rotating, described refractory tube is suspended on described tinsel, in order to by described conveyor system Support is provided through during described stove region to described wafer by described chip conveying, and in order to protect described crystalline substance the most completely Sheet is from the metal vapors emitted from described tinsel；

Iii) development length of described refractory tube is at least most of of described described length wiry, and at described metal It is positioned on silk only expose described short relative side wiry；

Iv) the transport parts separated for a pair, each of the pair of transport parts is transported parts and is arranged to and described tinsel An end adjacent, in described transport parts each formed continuous loop, described continuous loop through from stove entrance to described The described longitudinally processing conveyor path of outlet of still, then returns to described entrance on the return path outside described stove region；

V) each in described transport parts comprises along each in described transport parts continuous loop evenly spaced Multiple storage members, each described storage member is configured to removable and keeps described described short side wiry, institute State wire cloth to be set to be suspended between described transport parts across described transport width；And

C) being arranged in the drive system outside described stove region, described drive system arrangements becomes engagement said two to transport parts, with Along with described transport parts carry the plurality of refractory tube and the tinsel that is suspended between described storage member realize through The synchronizing moving in described region, during furnace operating, on described refractory tube by described chip conveying through described region with Described wafer is processed.

Continuous conveyor diffusion furnace the most according to claim 1, wherein said transport parts comprise in the following extremely Few one:

A) selected from band and the ring type parts of roller chain；

I) wherein when using band, described band comprises vertically extending support, and described wire end is accommodated in described support；

Ii) wherein when using roller chain, described roller chain comprises tubular pivot chain link, and described wire end is accommodated in described chain link In.

Continuous conveyor diffusion furnace the most according to claim 1, wherein said lower half region part is mounted to be fixed on frame Cannot move in frame, described stove comprises multiple powerpropelled vertical-lift parts, and described vertical-lift parts are arranged to even Receiving described upper and lower half stove region, part, described vertical-lift parts are arranged to relative to described fixing lower half district Territory part and promote described upper half area part, thus it is internal and allow access into the described stove thermal treatment zone to expose stove heating region Inside territory, in order to carry out on demand checking, adjust, maintenance and repair.

Continuous conveyor diffusion furnace the most according to claim 1, wherein said top half is mounted to fix in the frame Cannot move, described stove comprises multiple powerpropelled vertical-lift parts, and described vertical-lift parts are arranged attached to Described upper and lower half stove region, part, described vertical-lift parts are arranged to relative to described fixing upper half area portion Divide and reduce described half area part, thus expose described stove heating region inside and allow access into the described stove thermal treatment zone Inside territory, in order to carry out on demand checking, adjust, maintenance and repair.

Continuous conveyor diffusion furnace the most according to claim 1, comprises sagging brake unit molectron, described sagging braking Device assembly is arranged at least some of the latter half in described stove region, and between being arranged to below described bearing Separate and with described bearing side-by-side registration.

6. the continuous of photovoltaic (PV) solar cell wafer spreads or is total to a diffusion layer method of roasting, and described wafer has end table Face and top surface, said method comprising the steps of:

A) coating of at least one in described bottom wafer surface and described wafer top surface at least one adulterant compositions, to produce Raw multiple wafers, at least one in described top surface and basal surface of described wafer is carried out by one layer of adulterant compositions Doping；

B) transport the wafer after the plurality of described codope, from stove entrance to outlet of still, sequentially pass through multiple heating and cooling Region, described region is arranged by syntopy, in order to defining continuous print longitudinally processing conveyor path, described path is fixed To in less horizontal plane, and the described described top surface of chip oriented one-tenth is towards upper；

C) supporting described wafer in described transport step on low quality conveyor system, described conveyor system comprises diameter Little non-rotating refractory tube, described refractory tube supports described wafer, and described refractory tube hangs on the metal filament, described tinsel Across described wafer machining path and described from the second longitudinally outboard face in the first longitudinally outboard face of described stove to described stove Wafer constantly advances through described region by selected speed；

D) directly by the IR lamp radiation being mapped on described top surface and basal surface and thermal resistance radiation in described heating region Or described wafer is heated by least one in re-radiation, the time of heating be enough to promote that described adulterant is from described coating Layer is diffused in described wafer substrate material, thus completes at least one in p-n junction top surface layer and back contacts bottom surface layer Formation；And

E) by the radiation of the resistance that applied from longitudinal electrical resistance heating element heater maintain across described wafer machining path uniform Heat, described longitudinal electrical resistance heating element heater is arranged at least one in described heating region, adjacent with described lateral wall also And it is parallel to described lateral wall.

Method the most according to claim 6, wherein said heating region is along being substantially parallel to described machining path water The plane of average is divided into top heating region part and lower heater zone territory part, and from being arranged in the heating of at least one bottom Resistance radiant heater element in the part of region applies heat.

8. for silicon wafer is carried out a hot worked equipment, described wafer has top surface and basal surface, in diffusion With in metallization step, described equipment is arranged with exercisable combining form series winding:

A) at least one doping device module, is used for coating doped compositions, and described doped compositions combines selected from boron doped agent Thing and containing at least one in phosphorus dopant compositions；

B) continuous conveyor IR lamp heated type diffusion furnace equipment, described diffusion furnace equipment is after described doping device module receives doping Silicon wafer, described diffusion furnace equipment has long and narrow heating region, and described heating region is divided equally at carrier interbedded water and is slit into Upper part and low portion, and described diffusion furnace equipment comprises lifting device, described lifting device allows described upper part With low portion relative motion, in order to can enter the inside of described heating region, described stove is applicable to when using sidewall heating During device, the silicon wafer after doping is carried out diffusion roasting evenly；

C) ARC module, described ARC module arrangement is in the downstream of described diffusion furnace equipment, in order to from described Diffusion furnace equipment receives the silicon wafer after diffusion roasting, and comprises for coating anti-reflective at least top surface of described silicon wafer Penetrate the component of coating (ARC)；

D) printer/drier module, described printer/drier module is arranged in the downstream of described ARC module, In order to scribble the silicon wafer of ARC described in receiving, described printer/drier module comprises for connecing to the described basal surface coating back of the body Touch slurry and on described top surface the colelctor electrode circuit of printed with fine to produce the component of wafer after printing；

E) drier module, for receive the wafer after described printing and in the region of IR lamp heating by described printing after Wafer is heated to up to 650 DEG C, in order to the described slurry the described top surface of the silicon wafer after described printing and basal surface With circuit is burnt volatility organic bond；And

F) metallization furnace apparatus, described metallization furnace apparatus installs into the next downstream part at described drier module, described Metallization furnace apparatus has long and narrow heating region, and described heating region is divided equally at described carrier interbedded water and is slit into upper part And low portion, and described metallization furnace apparatus comprises lifting device, described lifting device allows described upper part and bottom Part relative motion, in order to can enter the inside of described heating region, described stove is applicable to carry out the silicon wafer after printing The metallization roasting of IR lamp heated type, burns in the range of 750 DEG C to 1100 DEG C with the speed of 80 DEG C to 150 DEG C per second；Thus produce Life can be processed into the silicon wafer of solar panel array, and described processing comprises cleaning, test and lamination.

The most according to claim 8 for silicon wafer carries out hot worked equipment, wherein said diffusion furnace equipment comprises:

A) multiple heating and cooled region, described region is to orient by the order of stove entrance to outlet of still, and described region is Arrange by syntopy, in order to by described region deviding continuous print longitudinally processing conveyor path, described path orients In less horizontal plane；

B) low quality conveyor system, is used for receiving solar cell wafer and making solar cell wafer add along described longitudinal direction Work conveyor path moves to described outlet of still from described stove entrance through described region, and described conveyor system includes:

I) multiple refractory metal silks separated, described tinsel is oriented crosscutting with described longitudinally processing conveyor path, institute State length wiry and define the useful chip conveying width through described stove region of described conveyor system；

Ii) refractory tube of non-rotating, described refractory tube is suspended on described tinsel, in order to by described conveyor system Support is provided through during described stove region to described wafer by described chip conveying, and in order to protect described crystalline substance the most completely Sheet is from the metal vapors emitted from described tinsel；

Iii) development length of described refractory tube is at least most of of described length wiry, and on described tinsel It is positioned to only expose described short relative side wiry；

Iv) the transport parts separated for a pair, each of the pair of transport parts is transported parts and is arranged to and described tinsel An end adjacent, in described transport parts each formed continuous loop, described continuous loop through from stove entrance to described stove The described longitudinally processing conveyor path of outlet, then returns to described entrance on the return path outside described stove region；

V) each in described transport parts comprises along each in described transport parts continuous loop evenly spaced Multiple storage members, each described storage member is configured to removable and keeps described described short side wiry, institute State wire cloth to be set to be suspended between described transport parts across described transport width；And

C) being arranged in the drive system outside described stove region, described drive system arrangements becomes engagement said two to transport parts, with Along with described transport parts carry the plurality of refractory tube and the tinsel that is suspended between described storage member realize through The synchronizing moving in described region, during furnace operating, by described chip conveying through described region on described refractory tube.

The most according to claim 8 for silicon wafer is carried out hot worked equipment, it comprises: the first doping device module, For coating boron doped agent compositions to the described basal surface of described wafer；And the second doping device module, for described Described top surface coating compositions Han phosphorus dopant of wafer, the wafer after doping is supplied to down by described first doping device module Dress device module, described upside-down mounting device module has for inverting described wafer so that described top surface is towards upper component, and institute State the wafer upwards of the top surface after reversion and be transferred to described second doping device module.