CN218826993U

CN218826993U - Deposition and diffusion process device for finely atomized impurity source

Info

Publication number: CN218826993U
Application number: CN202222875861.7U
Authority: CN
Inventors: 袁渊
Original assignee: Hangzhou Siftsem Semiconductor Co ltd
Current assignee: Hangzhou Siftsem Semiconductor Co ltd
Priority date: 2022-10-27
Filing date: 2022-10-27
Publication date: 2023-04-07
Anticipated expiration: 2032-10-27

Abstract

The utility model discloses a fine atomizing impurity source deposit diffusion process units solves the problem that power semiconductor device has large tracts of land chip diffusion doping inhomogeneous, repeatability is lower in the manufacturing process, can not satisfy the electric characteristic of major diameter discrete device and the problem that special application required. The device is including collection fog cover and the collection fog ware of setting at collection fog cover top, collection fog ware includes first port output and second port output, first port is connected with feed liquor atomizing unit, the second port links to each other with the unit that admits air, the junction of collection fog ware and collection fog cover is equipped with atomizer, the sealed complex slide holder in bottom of collection fog cover, the surface of collection fog cover is equipped with exhaust adjustment mechanism, the matter source is through the quiet liquid atomizing module, the triple fine atomization back of collection fog ware and fine atomization shower nozzle, can more even deposit carries out high concentration P + high temperature doping at the chip, guarantee the electric characteristic and the special application requirement that major diameter separates, show simultaneously and improve the production yield.

Description

Deposition and diffusion process device for fine atomized impurity source

Technical Field

The utility model relates to a power semiconductor processing technology field especially relates to a fine atomizing impurity source deposit diffusion process units.

Background

At present, the problems of uneven diffusion and doping of a large-area chip and low repeatability exist in the manufacturing process of a power semiconductor device, and the requirements of an extra-high voltage direct-current transmission project cannot be met.

For a long time, in the power semiconductor device processing industry, as P + region doping of a key process, a diffusion system that adopts a gas-carried liquid source diffusion system or adopts a venturi jet principle to directly jet an atomization source to the surface of a chip for further processing is traditionally adopted, and the following is a system working process.

The liquid impurity source carried by the gas is introduced from the gas inlet pipe at the tail end of the process pipe, is deposited on the surface of the chip, impurity atoms are diffused into the chip body after chemical reaction, and the carried gas and other reaction generated gas are discharged from the gas outlet pipe on the process pipe cover. Such diffusion systems suffer from the following drawbacks:

1. the entry of the source-carrying gas stream from the end of the process tube perpendicular to the surface of the wafer to be doped causes two adverse effects: (1) the concentration gradient of the doping source exists from the tail of the pipe to the pipe orifice, the concentration of the tail of the pipe is high all the time, and the concentration of the pipe orifice is low; (2) because the chips have an accumulated blocking effect on the trend of gas flow, the central part of each chip is most difficult to contact with a gas phase impurity source permeated in a zigzag manner, and therefore, the impurity concentration is lowest. The larger the chip area, the more pronounced this non-uniformity.

2. The venturi sprays the principle and utilizes high-pressure gas to form the negative pressure that high-speed air current produced through tiny mouth of pipe and drives pipe tail liquid and spray to chip local surface together, splashes to around under the high-speed striking of large granule liquid source and chip surface, and the sedimentary impurity of chip surface mainly comprises 3 aspects this moment: 1. and forming a large-particle liquid impurity source sprayed to the surface of the chip from the cone impurity source formed by the spray nozzle. 2. And (3) forming a mist impurity source by sputtering. 3. The air flow carries the mist particles to mutually collide in the space and fall to the impurity source on the surface of the chip.

It can be seen from these 3 main deposition modes that the impurity source distribution of the chip surface deposition is not uniform, and is influenced by air flow and pressure relief, the high concentration region is in the spray contact region, and the sputtering region is the second region, and each region has the falling impurity source distribution.

As described above, the conventional gas-carried liquid source doping method and the direct-injection impurity deposition method have inherent defects that the diffusion doping technical requirements of the large-diameter high-voltage discrete semiconductor device cannot be met.

Disclosure of Invention

The utility model discloses the main problem of having solved the traditional gas and carried the inhomogeneity of liquid source diffusion doping system and direct injection formula deposit method provides a fine atomizing formula deposit impurity source diffusion process units.

The utility model provides a technical scheme that its technical problem adopted is: the diffusion process device for depositing impurities by finely atomizing impurity sources comprises a mist collecting cover and a mist collector arranged at the top of the mist collecting cover, wherein the mist collector comprises a first port output and a second port output, the first port is connected with a liquid inlet atomizing unit, the second port is connected with an air inlet unit, an atomizing spray head is arranged at the joint of the mist collector and the mist collecting cover, a wafer carrying table in sealing fit with the mist collecting cover is arranged at the bottom of the mist collecting cover, and after the impurity sources are subjected to three times of fine atomization by the liquid inlet atomizing unit, the mist collector and the fine atomizing spray head, high-concentration P + high-temperature doping can be carried out on a chip by more uniform deposition, the electrical characteristics and the special application requirements of large-diameter discrete devices are ensured, and the production yield is obviously improved.

As a preferred scheme of the scheme, the fog collecting cover comprises an inner cover body and an outer cover body, a gap is formed between the inner cover body and the outer cover body, and the fog collecting cover can independently control airflow and exhaust, so that the impurity source has high uniformity, the fluctuation caused by sudden pressure relief is avoided, and the standard deviation value of the average sheet resistance in different batches is reduced.

As an optimal scheme of the scheme, the outer layer cover body of the mist collection cover is provided with exhaust holes, the inner layer cover body of the mist collection cover is at least provided with an adjusting surface, adjusting holes are formed in the adjusting surface, adjusting plates for adjusting the opening and closing of the adjusting holes are inserted in the adjusting surface, the exhaust holes in the outer layer cover body can be used for conveniently protecting the environment for manufacturing chips, adjusting plate exhaust holes are formed in the pressure adjusting plate and matched with the adjusting valves, and the deposition positions of atomized solvents are finely adjusted by adjusting the exhaust amount and the direction in the mist collection cover.

As a preferred scheme of the scheme, the adjusting holes are provided with a plurality of adjusting holes which are respectively arranged at the upper part, the middle part and the lower part of the adjusting surface, the falling direction of impurities can be effectively controlled through the adjusting holes at the upper part of the adjusting surface, the concentration of the impurities can be controlled through the adjusting holes at the middle part, and the impurities precipitated on the surface of the chip can be cleaned through the adjusting holes at the lower part.

As a preferred scheme of the scheme, the clamping groove is formed in the end face of the bottom of the fog collecting cover, the sealing ring is nested in the clamping groove, the edge of the outer ring of the slide holder is in closed pressure connection with the bottom of the fog collecting cover, the fog collecting cover and the slide holder can be tightly connected by using the sealing ring and a ring at the edge of the outer ring of the slide holder, and the air tightness of the device is guaranteed.

As an optimal scheme of the scheme, a plurality of stepped radial ring surfaces are arranged along the inner wall of the mist collecting cover, a clamping groove is formed in each stepped radial ring surface, a sealing ring is embedded in each clamping groove, each sheet carrying platform comprises a plurality of sheet carrying platforms with different diameters, the sheet carrying platforms are hermetically matched with the corresponding stepped radial ring surfaces, and platforms capable of being loaded can be provided for chips with different sizes by the sheet carrying platforms with different sizes, so that the process device can perform quality source deposition work for various chips, and the usability of the device is improved.

As a preferable scheme of the above scheme, the liquid inlet atomizing unit includes a solvent guide pipe and a solution bottle containing a solvent, the solvent guide pipe includes an outer pipe and an inner pipe which are nested with each other, the outer pipe and the inner pipe form a liquid guide channel, the outer pipe is inserted into the solution bottle, the inner pipe penetrates through the solution bottle and is connected with the nitrogen generating device, and the solvent can be drawn into the mist collector from the solvent bottle through the outer solvent guide pipe due to the negative pressure of the atmosphere by the high-purity nitrogen.

As a preferable scheme of the scheme, a stop valve is arranged between the mist collector and the atomizing nozzle, and the starting and closing work of the atomizing nozzle is realized through the opening and closing of the stop valve.

As an optimal selection scheme of the scheme, the adjusting plate is fixed on the surface of the adjusting hole through the guide rail, and the adjusting plate can slide uniformly by using the guide rail, so that the chip manufacturing process is controlled more accurately.

As a preferred scheme of the scheme, the device further comprises a lifting mechanism, the slide holder is arranged on the upgrading mechanism, the lifting mechanism is driven by a hydraulic or electric module, the hydraulic or electric module can operate the slide holder more stably, and damage to the chip in the using process of the device can be effectively avoided.

The utility model has the advantages that:

1. after the impurity source is subjected to three times of fine atomization through the liquid inlet atomization unit, the mist collector and the fine atomization nozzle, the impurity source can be more uniformly deposited on a chip to perform high-concentration P + high-temperature doping, the electrical characteristics and special application requirements of a large-diameter discrete device are ensured, and meanwhile, the production yield is remarkably improved.

2. Double-deck cover can be controlled air current and exhaust alone, make the impurity source have high homogeneity, the volatility that the sudden pressure release brought has been avoided, the standard deviation value of different batch average sheet resistance has been reduced, exhaust hole at the outer cover body, the environment of protection chip manufacturing can be convenient for, there is the regulating plate exhaust hole on the pressure regulating plate, the cooperation governing valve, through adjusting displacement and the direction in the collection fog cover, finely tune the deposit position of atomizing solvent, through the regulation hole on regulating surface upper portion, the direction of wafing of can effective control impurity, through the regulation hole at middle part, can control the concentration of impurity, through the regulation hole of lower part, can clear up the impurity of deposiing on the chip surface.

3. The sealing ring and the circular ring at the edge of the outer ring of the slide holder are used for tightly connecting the mist collecting cover and the slide holder, so that the air tightness of the device is ensured, and a platform capable of being loaded can be provided for chips with different sizes, so that the process device can perform mass source deposition work for various chips, and the usability of the device is improved.

4. In the inlayer pipe, high-purity nitrogen gas can be with the solvent because the atmospheric negative pressure passes through outer solvent honeycomb duct from the solvent bottle and pulls to the collection fog ware in, through opening and closing of stop valve, realizes opening and closing work of diffusion technology, and hydraulic pressure or electronic module can be more steady operation objective table, can effectively avoid the device to change the in-process to the damage of chip.

Drawings

The present invention will be further described with reference to the accompanying drawings and examples.

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is another schematic structural diagram of the present invention.

Reference numerals:

1. a nitrogen inlet; 2. a mist collector; 3. a stop valve; 4. a mist collecting cover; 5. an air exhaust port; 6. adjusting a valve; 7. a pressure adjustment plate; 8. an exhaust hole; 9. adjusting plate exhaust holes; 10. a seal ring clamping groove; 11. an atomizing spray head; 12. solvent honeycomb duct, 13, solvent bottle; 16. a slide holder.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments in conjunction with the accompanying drawings.

Example (b):

in the embodiment, nitrogen is sent into a solvent flow guide pipe 12 from a nitrogen inlet 1, high-purity nitrogen with proper pressure (about 0.2 to 0.3 mp) is introduced into a mist collector 2 from an inner pipe of the solvent flow guide pipe 12, a solvent in a solvent bottle 13 is drawn into the mist collector 2 along with atmospheric negative pressure of the solvent flow guide pipe 12, the solvent in the mist collector is broken into large-particle source-carrying powder and liquid source-carrying mist droplets, an atomizing nozzle 11 arranged at the bottom of the mist collector 2 atomizes the powder and the liquid source-carrying mist droplets into finer and smaller source-carrying impurities secondarily and expands the finer and smaller source-carrying impurities into a cone-shaped mist collecting cover 4, the impurity source in the mist collecting cover is deposited on a chip supported by a chip carrier 16, and the impurity source can be deposited on the chip in a more uniform manner to perform high-concentration P + high-temperature doping after the impurity source is subjected to tertiary fine atomization by a liquid inlet atomizing unit, the mist collector and the fine atomizing nozzle, so that the yield of large-diameter devices is remarkably improved, and the yield of the devices is remarkably improved.

Further, the mist collecting cover 4 comprises an inner cover body and an outer cover body, a gap is formed between the inner cover body and the outer cover body, the outer cover body of the mist collecting cover 4 is provided with exhaust holes, the inner cover body of the mist collecting cover 4 is at least provided with an adjusting surface, the adjusting surface is provided with adjusting holes 8, adjusting plates 7 for adjusting the opening and closing of the adjusting holes are inserted into the mist collecting cover 4, the adjusting holes 8 are multiple and are respectively arranged at the upper part, the middle part and the lower part of the adjusting surface, the double-layer cover body can independently control air flow and exhaust, so that an impurity source has high uniformity, the fluctuation caused by sudden pressure relief is avoided, the standard deviation value of the average sheet resistance among different batches is reduced, the exhaust holes in the outer cover body can be used for conveniently protecting the environment for manufacturing chips, the pressure adjusting plates are provided with adjusting plate exhaust holes, the adjusting valves are matched, the deposition positions of atomized solvents can be finely adjusted by adjusting the exhaust amount and the direction in the mist collecting cover, the adjusting holes in the upper part of the adjusting surfaces of the chips can be effectively controlled, the impurities can be precipitated through the adjusting holes in the middle parts, the concentration of the impurities can be controlled, and the impurities can be cleared through the adjusting holes in the surfaces of the chip surfaces of the chips.

Furthermore, a clamping groove 10 is formed in the end face of the bottom of the mist collecting cover 4, a sealing ring is nested in the clamping groove, the edge of the outer ring of the slide holder 16 is in closed pressure connection with the bottom of the mist collecting cover, the sealing ring and a circular ring at the edge of the outer ring of the slide holder can be tightly connected with the mist collecting cover and the slide holder, the air tightness of the device is guaranteed, and when the device is in actual use, the circular ring is partially extruded to deform, so that an airtight space can be obtained.

In order to solve the problem of impurity diffusion of larger chips, as shown in fig. 2, a plurality of stepped radial ring surfaces are arranged along the inner wall of a mist collection cover 4, a clamping groove 10 is arranged on each stepped radial ring surface, a sealing ring is nested in each clamping groove 10, a wafer carrying table 16 comprises a plurality of wafer carrying tables 16 with different diameters, for the wafer carrying tables 16 with different diameters, the problem that chips with different sizes are placed in an atomizing doping process of actual chips and uniform diffusion needs to be carried out in a larger area is mainly solved, the wafer carrying tables 16 are closely matched with the corresponding stepped radial ring surfaces, the inner wall of the multi-step mist collection cover 4 is matched with the wafer carrying tables 16 with different sizes, a platform capable of being loaded can be provided for the chips with different sizes, in the actual use process, the wafer carrying tables can be moved downwards in the face of manufacturing of the chips with larger sizes, the diameter which the wafer carrying tables are actually usable is increased, and the application range of the device is wider.

Furthermore, a stop valve 3 is arranged between the mist collector 2 and the atomizing nozzle 11, and the normal operation of the atomizing nozzle device is realized by opening or closing the stop valve. The diffusion process device for the fine atomization impurity source deposition impurities further comprises a lifting mechanism, and the slide holder 16 is arranged on the upgrading mechanism. The lifting mechanism is driven by a hydraulic or electric module, when the lifting mechanism faces a large-size chip to be manufactured, the lifting platform is controlled to descend, and when a small-size chip is manufactured, the lifting platform is controlled to ascend, so that the device can be subjected to more stable and accurate chip manufacturing control.

The invention has the advantages that the standard deviation sigma of the sheet resistance of the doped 6-inch chip is reduced to 3.1 percent from the previous 8 percent; the standard deviation of the average sheet resistance of the chips of different batches is reduced from 12 percent to 4.5 percent. Therefore, the doping uniformity is greatly improved no matter in the same chip or between chips in different batches, and the air inlet and exhaust modes of the secondary high-purity nitrogen and the conical mist collection cover better shield the fluctuation caused by sudden pressure relief due to more use areas of nitrogen pressure in the production process, reduce the standard deviation value of the average sheet resistance in different batches and increase the radial uniformity of the concentration of a P + area in the same chip. The yield of the 6-inch 5000A/8500V ultrahigh-voltage thyristor is increased from 70% to 79%, and simulation shows that the method can meet the technical requirement of open-tube diffusion doping of 8-inch discrete devices, and is a major-diameter high-voltage attack and attack key technical fort of discrete semiconductor devices.

Claims

1. A deposition and diffusion process device for a finely atomized impurity source is characterized in that: including collection fog cover (4) and set up collection fog ware (2) at collection fog cover top, collection fog ware (2) are including first port output and second port output, and first port is connected with feed liquor atomizing unit, and the second port links to each other with air inlet unit (1), and collection fog ware (2) are equipped with atomizer (11) with the junction of collection fog cover (4), are equipped with rather than sealed complex slide holder (16) bottom collection fog cover (4).

2. The deposition and diffusion process unit of claim 1, wherein said mist collection enclosure (4) comprises an inner enclosure and an outer enclosure with a gap therebetween.

3. The deposition and diffusion process device of the finely atomized impurity source as claimed in claim 2, wherein the outer cover body of the mist collection cover (4) is provided with an exhaust hole, the inner cover body is provided with at least one adjusting surface, the adjusting surface is provided with an adjusting hole (8), and the mist collection cover (4) is inserted with an adjusting plate (7) for adjusting the opening and closing of the adjusting hole.

4. The deposition and diffusion process apparatus for finely atomized impurity source as claimed in claim 3, wherein said regulating hole (8) has a plurality thereof, and is provided at an upper portion, a middle portion and a lower portion of the regulating surface, respectively.

5. The deposition and diffusion process device of the finely atomized impurity source as claimed in claim 1, wherein the bottom end face of the mist collection cover (4) is provided with a clamping groove (10), a sealing ring is nested in the clamping groove, and the edge of the outer ring of the slide holder (16) is in sealed pressure joint with the bottom of the mist collection cover.

6. The deposition and diffusion process device of the finely atomized impurity source as claimed in claim 5, wherein a plurality of stepped radial ring surfaces are arranged along the inner wall of the mist collection cover (4), each stepped radial ring surface is provided with a clamping groove (10), a sealing ring is nested in each clamping groove (10), the slide holder (16) comprises a plurality of slide holders (16) with different diameters, and the slide holders (16) are in close fit with the corresponding stepped radial ring surfaces.

7. The deposition and diffusion process device of the finely atomized impurity source as claimed in claim 1, wherein the liquid inlet atomization unit comprises a solvent guide pipe (12) and a solution bottle (13) containing the solvent, the solvent guide pipe (12) comprises an outer pipe and an inner pipe which are nested with each other, the outer pipe and the inner pipe form a liquid guide passage, the outer pipe is inserted into the solution bottle, and the inner pipe passes through the solution bottle (13) and is connected with the nitrogen generation device.

8. The deposition and diffusion process device of the finely atomized impurity source as claimed in claim 1, wherein a stop valve (3) is provided between the mist collector (2) and the atomizing nozzle (11).

9. The deposition and diffusion process apparatus for finely atomized impurity source as claimed in claim 6, wherein the apparatus further comprises an elevating mechanism, and the stage (16) is provided on the elevating mechanism.