CN217588864U

CN217588864U - Wet etching equipment with preheating function

Info

Publication number: CN217588864U
Application number: CN202221285582.9U
Authority: CN
Inventors: 朴灵绪; 吴镐硕; 张怀东
Original assignee: Suzhou Enteng Semiconductor Technology Co ltd
Current assignee: Suzhou Enteng Semiconductor Technology Co ltd
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2022-10-14
Anticipated expiration: 2032-05-25

Abstract

The utility model provides a wet etching equipment of area function of preheating, including the sculpture groove that preheats that is used for bearing sculpture liquid and treats the sculpture piece and be used for preheating the groove, preheat the groove and be linked together with the sculpture liquid source, certainly the sculpture liquid warp of sculpture liquid source supply preheat the groove after preheat supply extremely in the sculpture groove, preheat the groove including preheating the cell body and being located preheat the preheating device on the cell body. The utility model discloses through the structural design who improves, set up outside the sculpture cell body and preheat the cell body, the sculpture liquid of treating to supply can be carried to the sculpture cell body after preheating the cell body to required process temperature earlier again, can effectively improve equipment output rate, avoids simultaneously because of the danger of heating production in the sculpture cell body, helps improving the production security.

Description

Wet etching equipment with preheating function

Technical Field

The utility model relates to a semiconductor manufacturing technical field especially relates to wet etching process equipment, especially relates to a wet etching equipment of area preheat function.

Background

In the process of preparing the wafer, the etching process is used for removing damaged layers with different depths on the surface of the wafer, which are generated in the mechanical processing step. The instant etching process is to prevent the defects caused by the processing deterioration layer on the surface and edge of the wafer after the steps of slicing, edge polishing, surface polishing, etc. from remaining on the wafer. In order to ensure the quality of the device manufactured subsequently, the residual defect layer must be removed.

The process of removing these residual defect layers is mostly chemical etching. According to the requirements of customers, in the wafer preparation process, alkaline etching using KOH or acid etching using a mixed acid etchant containing HF/HNO3 and additives is adopted. In the alkaline etching process, an SC-2 etching groove is adopted after a KOH etching groove, the concentration of KOH is 30-50%, and the temperature is 60-90 ℃. The etch rate generally increases with increasing concentration of the alkaline etchant until reaching a peak and then begins to decrease. And then, adopting HCL/HF/H2O2 etching liquid in the SC-2 etching groove to remove the silicate and the metal impurities on the surface of the wafer. The currently used alkaline etchant generally needs to be heated from normal temperature to about 80 ℃, and the heating method generally adopts a circulating heater (with the power of 8 KW) to directly heat KOH in an etching groove. Typically 90 liters (Liter) of KOH require approximately 60 minutes or more to heat to this temperature, which results in extended equipment start-up times and reduced throughput.

In the KOH cleaning equipment used in batch type wet etching, the mass percentage concentration of the used alkaline etchant is preferably 50.6-55.0 wt%, and the temperature is 65-85 ℃. Within this concentration and temperature range, a proper etching rate can be obtained (too slow etching rate results in low production efficiency, and too fast etching rate results in too high etching selectivity ratio and thus rough wafer surface). Meanwhile, the problem of the equipment caused by the fact that the temperature of the etching liquid is too high is not expected, for example, the etching liquid is in great danger when boiling, or the wafer is in danger when being taken and placed.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing prior art's shortcoming, an object of the utility model is to provide a wet etching equipment of area preheat function for adopt circulation heater directly to heat the sculpture liquid of sculpture inslot at the sculpture inslot among the solution prior art, lead to equipment output rate to descend, and lead to production safety scheduling problem because of the sculpture liquid boiling.

For realize above-mentioned purpose and other relevant purposes, the utility model provides a wet etching equipment of function preheats in area, including being used for bearing the sculpture liquid and treating the sculpture groove of sculpture piece and being used for the preheating groove that preheats, it is linked together with the sculpture liquid source to preheat the groove, certainly the sculpture liquid warp of sculpture liquid source supply preheat the groove after supply extremely in the sculpture groove, preheat the groove including preheating the cell body and being located preheat the preheating device on the cell body.

Optionally, the preheating tank is located right above the etching tank, the supply pipeline extends downwards from the preheating tank to the inside of the etching tank, and a valve is arranged on the supply pipeline.

Optionally, the heating power of the preheating device is 18KW.

Optionally, a temperature control device is further disposed on the preheating tank, and the temperature control device is communicated with the preheating device.

Optionally, the etching groove is a KOH etching groove, and the etching liquid is a KOH etching liquid.

Optionally, the preheating tank body is made of PTFE.

Optionally, the etching liquid source is a CCSS supply source.

Optionally, the wet etching equipment with the preheating function further comprises a recycling pipeline, a liquid pump, a filter and a heating device, two ends of the recycling pipeline are communicated with the etching tank, and the liquid pump, the filter and the heating device are sequentially arranged on the recycling pipeline so as to convey the residual etching liquid discharged from the etching tank into the etching tank again after being filtered and heated.

More optionally, the wet etching apparatus with the preheating function further includes a damper located between the liquid pump and the filter.

Optionally, a mass flow meter is further disposed on the recovery pipeline, and the mass flow meter is located on the recovery pipeline between the heating device and the etching tank.

As mentioned above, the utility model discloses a wet etching equipment of function is preheated in area has following beneficial effect: the utility model discloses through the structural design who improves, set up outside the sculpture cell body and preheat the cell body, the sculpture liquid of treating to supply can be carried to the sculpture cell body after preheating the cell body to required process temperature earlier again, can effectively improve equipment output rate, avoids simultaneously because of the danger of heating production in the sculpture cell body, helps improving the production security.

Drawings

Fig. 1 shows a schematic structural diagram of the wet etching apparatus with preheating function provided by the present invention.

Description of the element reference numerals

11. Etching groove

12. Preheating tank

121. Preheating tank body

122. Preheating device

123. Supply line

124. Temperature control device

13. Etching liquid source

14. Recovery pipeline

15. Liquid pump

16. Filter

17. Heating device

18. Damper

19. Mass flowmeter

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The present invention can be implemented or applied by other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to fig. 1. It should be noted that the drawings provided in the present embodiment are only for schematically illustrating the basic concept of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, amount and proportion of each component in actual implementation can be changed at will, and the layout of the components may be more complicated.

The etching rate of the KOH etching solution at 80 ℃ is 0.03-0.04 um/sec, and the service life of the etching solution is 30-50 etching periods (namely, 30-50 batches of wafers can be etched by the etching solution in one groove). The factors determining the service life of the KOH etching solution are the etching rate of the surface of the wafer and the chemical pollution condition of the surface of the wafer. After the etching solution reaches the preset service life, the new KOH etching solution is required to be replaced, and then the heater in the KOH etching tank is adopted to heat the new KOH etching solution for more than 60 minutes so as to enable the temperature to reach 80 ℃. This results in a decrease in the plant output rate. Therefore, the utility model provides an improve the countermeasure.

Specifically, as shown in fig. 1, the utility model provides a wet etching equipment of area preheat function, including being used for bearing the weight of etching liquid and treating the etching groove 11 of sculpture piece and being used for preheating groove 12, preheating groove 12 is linked together with sculpture liquid source 13, certainly the etching liquid warp of sculpture liquid source 13 supply preheat groove 12 after supply extremely in the etching groove 11, preheating groove 12 is including preheating the cell body 121 and being located preheat the preheating device 122 on the cell body, etching groove 11 includes the sculpture cell body, is used for bearing the weight of etching liquid and treats the sculpture piece, for example the wafer in the sculpture cell body. The utility model discloses through the structural design who improves, set up outside the sculpture cell body and preheat the cell body, treat that the sculpture liquid of replenishment can be carried to the sculpture cell body after preheating the cell body to required process temperature earlier, can effectively improve equipment yield, avoid simultaneously because of the danger of heating production in the sculpture cell body, for example avoid splashing or get when the etching liquid boils and put the wafer in-process and cause personnel's injury, help improving the production security.

As an example, the etching tank body is usually provided with a liquid discharge port for discharging the etching liquid in the tank body when the etching liquid needs to be replaced. The material of the etching tank and the preheating tank 121 may be the same, for example, both are transparent and corrosion resistant. In an example, the preheating tank 121 is made of PTFE (polytetrafluoroethylene), and the preheating tank 121 is preferably a closed tank to prevent the liquid from splashing when the etching liquid is heated and boiled. The etching tank body can be a tank with an opening at the top, or can further comprise an inner tank and an outer tank positioned outside the inner tank, the supply pipeline is communicated to the inner tank, and the etching liquid overflowing from the inner tank flows into the outer tank to realize cyclic regeneration.

Theoretically, the preheating tank body 121 may be located at any suitable position as long as the etching solution in the preheating tank body 121 can be conveyed into the etching tank body. However, in a better example, the height of the preheating tank body 121 is higher than that of the etching tank body, so that the etching liquid can flow into the etching tank body from the preheating tank body 121 by using the gravity action under the condition that a power pump is not needed, which not only helps to reduce the use of the power pump and reduce the equipment cost, but also can effectively avoid the pollution possibly caused by the use of the power pump. In an example, the preheating tank 12 is located right above the etching tank 11, the supply pipe 123 extends downward from the preheating tank 12 into the etching tank 11, and a valve (not shown, the valve may be an electric valve, and the opening and closing of the valve can be controlled by a controller) can be disposed on the supply pipe 123, so that when a new liquid needs to be replenished, the valve is opened, and the etching liquid flows down into the etching tank. In addition, the preheated etching liquid is supplied into the etching groove from top to bottom, so that the preheated new liquid and the original etching liquid in the etching groove can be fully mixed, and the temperature of the etching liquid is uniform and stable as soon as possible.

In an example, a driving device communicating with the preheating tank body or only with the supply pipeline 123 may be further included to move the position, e.g. height, of the supply pipeline 123 when needed, for example, when liquid replenishment is needed, the supply pipeline is lowered into the etching tank body, and as the liquid level in the etching tank gradually rises, the height of the supply pipeline 123 is gradually raised to separate from the etching tank, so as to avoid the supply pipeline from being immersed in the etching liquid. The wet etching apparatus may further include a support frame (not shown) for placing the supply line during non-replenishment, and the support frame may be fixed to the top of the etching bath, for example.

The preheating device 122 includes, but is not limited to, a resistance heater. As an example, the heating power of the preheating device 122 is 18KW, which can significantly improve the heating efficiency compared to the heater with 8KW commonly used in the prior art.

For precise control of the heating temperature, as an example, a temperature control device 124 is further disposed on the preheating tank 12, the temperature control device 124 is communicated with the preheating device 122, and the temperature control device 124 may further include a liquid crystal display module for displaying the temperature.

The utility model discloses a wet etching equipment can be for the equipment of carving based on KOH etching liquid, so etching groove 11 is KOH etching groove, etching liquid is corresponding KOH etching liquid. The process temperature of the KOH etching equipment is usually about 80 ℃, and a long time is needed for heating to the required process temperature, but the preheating function is arranged outside the etching groove 11 in the application, so that the extra time of the etching groove is not occupied, and the output rate of the equipment is improved. Of course, in other examples, the wet etching apparatus may also be an apparatus of another process type, that is, the etching solution may be of another type, and this embodiment is not limited strictly.

As an example, the etching liquid source 13 is a CCSS (Central Chemical Supply System) Supply source, and is helpful to reduce the production cost and improve the safety management level through centralized management. An electrically controlled valve and a mass flow meter (not shown) may be provided on the supply lines of the etching liquid source 13 and the preheating bath body 121.

For reducing waste liquid discharge, reducing production cost and reducing environmental pollution, as an example, the wet etching equipment with the preheating function further comprises a recycling pipeline 14, a liquid pump 15, a filter 16 and a heating device 17, two ends of the recycling pipeline 14 are communicated with the etching groove 11, and the liquid pump 15, the filter 16 and the heating device 17 are sequentially arranged on the recycling pipeline 14 so as to re-convey residual etching liquid discharged from the etching groove 11 into the etching groove 11 after being filtered and heated. The heating device 17 can likewise be a resistance heater, the power of which can be set as required, for example, likewise 18KW. The wet etching equipment can be further provided with a concentration meter which is positioned in the etching groove and used for detecting the concentration of the etching liquid in the etching groove, and the amount of the new liquid supplemented in the preheating groove is adjusted according to the measuring result of the concentration meter.

In a further example, the wet etching apparatus with preheating function further includes a damper 18 between the liquid pump 15 and the filter 16. The damper 18 is provided to reduce the vibration of the apparatus caused by the operation of the liquid pump 15, and to contribute to the improvement of the stability of the apparatus during the operation.

As an example, a mass flow meter 19 is further disposed on the recycling line 14 between the heating device 17 and the etching tank 11, so that the flow rate of the etching solution can be precisely measured.

The wet etching equipment also comprises a control device, such as a PLC (programmable logic controller) or a central controller, wherein the control device is communicated with the above-mentioned electrically-controllable devices such as the etching tank, the preheating device, the valve, the liquid pump and the like so as to control the operation of each device according to process parameters and improve the automation level of the equipment. For example, the etching liquid source is controlled to supply a predetermined amount of etching liquid into the preheating tank, the preheating device is started to preheat, after the etching tank finishes a predetermined etching process, the etching tank is controlled to discharge liquid, the liquid pump starts to work, the discharged residual liquid is conveyed to the filter to be filtered and heated, then the preheating tank is controlled to supply liquid to the etching tank (the recovered liquid and the preheating tank can supply liquid simultaneously or mainly or secondarily by the preheating tank, and no limitation is specifically made), the etching tank starts to perform the etching process after the liquid supply is finished, and the etching liquid source can supply liquid to the preheating tank again to start a new round of preheating. Of course, the process is only exemplary, the starting point of each part is not strictly limited, but may be adjusted according to the process requirement, and is not strictly limited in this embodiment.

The utility model discloses a wet etching equipment sets up the heating process of etching liquid outside the sculpture cell body, can improve the operating rate of sculpture cell body, reduces personnel's injury (because the staff need with sculpture cell body frequent contact).

To sum up, the utility model provides a wet etching equipment of area preheat function, including the sculpture groove that preheats that is used for bearing sculpture liquid and treats the sculpture piece and be used for preheating, it is linked together with the sculpture liquid source to preheat the groove, certainly the sculpture liquid warp of sculpture liquid source supply preheat the groove after preheat supply extremely in the sculpture groove, preheat the groove including preheating the cell body and being located preheat the preheating device on the cell body. The utility model discloses through the structural design who improves, set up outside the sculpture cell body and preheat the cell body, the sculpture liquid of treating to supply can be carried to the sculpture cell body after preheating the cell body to required process temperature earlier again, can effectively improve equipment output rate, avoids simultaneously because of the danger of heating production in the sculpture cell body, helps improving the production security. Therefore, the utility model effectively overcomes various defects in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention shall be covered by the claims of the present invention.

Claims

1. The wet etching equipment with the preheating function is characterized by comprising an etching groove and a preheating groove, wherein the etching groove is used for bearing etching liquid and a part to be etched, the preheating groove is used for preheating, the preheating groove is communicated with an etching liquid source, etching liquid supplied by the etching liquid source is preheated by the preheating groove and then is supplied to the etching groove, and the preheating groove comprises a preheating groove body and a preheating device located on the preheating groove body.

2. The wet etching apparatus with the preheating function according to claim 1, wherein the preheating groove is located right above the etching groove, and the supply line extends downward from the preheating groove into the etching groove.

3. The wet etching apparatus with the preheating function according to claim 1, wherein a heating power of the preheating device is 18KW.

4. The wet etching apparatus with the preheating function according to claim 1, wherein a temperature control device is further disposed on the preheating tank, and the temperature control device is in communication with the preheating device.

5. The wet etching apparatus with the preheating function according to claim 1, wherein the etching groove is a KOH etching groove, and the etching solution is a KOH etching solution.

6. The wet etching equipment with the preheating function as claimed in claim 1, wherein the preheating tank body is made of PTFE.

7. The wet etching apparatus with the preheating function as claimed in claim 1, wherein the etching liquid source is a CCSS supply source.

8. The wet etching apparatus with the preheating function according to any one of claims 1 to 7, further comprising a recycling pipeline, a liquid pump, a filter and a heating device, wherein two ends of the recycling pipeline are communicated with the etching tank, the liquid pump, the filter and the heating device are sequentially arranged on the recycling pipeline, and residual etching liquid discharged from the etching tank is filtered, heated and then re-conveyed into the etching tank.

9. The wet etching apparatus with the preheating function according to claim 8, further comprising a damper located between the liquid pump and the filter.

10. The wet etching apparatus with the preheating function according to claim 8, wherein a mass flow meter is further disposed on the recovery pipeline between the heating device and the etching tank.