CN214099608U

CN214099608U - Wafer storage device

Info

Publication number: CN214099608U
Application number: CN202023026414.1U
Authority: CN
Inventors: 宋亮东; 韩丽娜; 杨剑
Original assignee: Yangtze Memory Technologies Co Ltd
Current assignee: Yangtze Memory Technologies Co Ltd
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2021-08-31
Anticipated expiration: 2030-12-16

Abstract

The utility model relates to a semiconductor manufacturing technology field especially relates to a wafer storage device. This wafer storage device includes: the unit space is used for storing a conveying box, and the conveying box is used for bearing a plurality of wafers; and the purging structure is used for performing gas purging on the unit space so as to control the humidity inside the unit space. The utility model discloses reduce the damage problem of having avoided the wafer in the storage process even, improved the security of wafer in the storage process, ensured the quality of wafer product.

Description

Wafer storage device

Technical Field

The utility model relates to a semiconductor manufacturing technology field especially relates to a wafer storage device.

Background

With the development of the planar flash memory, the manufacturing process of the semiconductor has been greatly improved. In recent years, however, the development of planar flash memories has met with various challenges: physical limits, existing development technology limits, and storage electron density limits, among others. In this context, to solve the difficulties encountered by flat flash memories and to pursue lower production costs of unit memory cells, various three-dimensional (3D) flash memory structures, such as 3D NOR (3D NOR) flash memory and 3D NAND (3D NAND) flash memory, have come into force.

The 3D NAND memory is based on the small volume and the large capacity, the design concept of the three-dimensional mode layer-by-layer stacking height integration of the storage units is adopted, the memory with high unit area storage density and high-efficiency storage unit performance is produced, and the mainstream process of the design and production of the emerging memory is formed.

During the storage process of wafer products such as 3D NAND memories, the metal pads are often damaged due to exposure to air, which eventually leads to package bonding failure in the back-end process of the integrated circuit or causes problems such as low bonding reliability.

Therefore, how to prevent the wafer from being damaged during the storage process and improve the quality of the wafer product is a technical problem to be solved urgently at present.

SUMMERY OF THE UTILITY MODEL

The utility model provides a wafer storage device for solve the wafer product among the prior art and easily suffer the problem of damage in the storage process, with the quality that improves the wafer product.

In order to solve the above problems, the present invention provides a wafer storage device, including:

the unit space is used for storing a conveying box, and the conveying box is used for bearing a plurality of wafers;

and the purging structure is used for performing gas purging on the unit space so as to control the humidity inside the unit space.

Optionally, the number of the unit spaces is multiple;

the plurality of unit spaces are arranged in a three-dimensional array.

Optionally, the number of the purging structures is multiple, and the plurality of purging structures correspond to the plurality of unit spaces one to one.

Optionally, the purge structure includes:

the gas inlet pipeline extends from the outside to the inside of the unit space and is used for transmitting purge gas to the unit space;

and the air outlet pipeline extends from the inside of the unit space to the outside and is used for discharging the waste gas in the unit space.

Optionally, the purging structure further includes:

the one-way air inlet valve is arranged on the air inlet pipeline and used for controlling whether the air inlet pipeline is conducted or not;

and the one-way air outlet valve is arranged on the air outlet pipeline and used for controlling whether the air outlet pipeline is conducted or not.

Optionally, the purging structure further includes:

and the controller is connected with the one-way air inlet valve and the one-way air outlet valve and used for controlling the one-way air inlet valve and the one-way air outlet valve to be periodically opened.

Optionally, the purging structure further includes:

and a sensor disposed inside the unit space, for detecting humidity inside the unit space.

Optionally, the controller is connected to the sensor, and is configured to adjust a flow rate of the purge gas delivered to the unit space according to the humidity inside the unit space detected by the sensor.

Optionally, the method further includes:

and the buffer chamber is positioned outside the unit space and used for receiving the transfer box from the outside and adjusting the vacuum degree in the transfer box.

Optionally, the transfer box is a front-opening wafer transfer box or a front-opening shipping box.

The utility model provides a wafer storage device is used for storing the unit space of conveying box through setting up to it is right to set up the structure of sweeping the inside gas of carrying on of unit space sweeps, thereby realizes right the control of the inside humidity of unit space avoids because of the too big problem that leads to the wafer damage of the inside humidity of unit space has improved the security in the wafer storage process, has ensured the quality of wafer product.

Drawings

Fig. 1 is a schematic cross-sectional view of a wafer storage device according to an embodiment of the present invention;

fig. 2 is a schematic top view of a wafer storage device according to an embodiment of the present invention.

Detailed Description

The following describes in detail a specific embodiment of a wafer storage device according to the present invention with reference to the accompanying drawings.

Aluminum has long been widely used as an interconnect material for Back End of Line (BEOL) integrated circuit fabrication processes due to its low cost, low resistivity and high compatibility with silicon wafer processes in the fabrication of wafer products such as 3D NAND memories. However, when aluminum is used as the top metal layer, after the passivation layer is etched and a PAD (PAD) window is opened in the semiconductor process, the PAD formed by aluminum is exposed to the air, and thus is very susceptible to electrochemical reaction with moisture and fluorine atoms (or fluorine-containing molecules) in the air, and crystal defects (such as crystal AlO) are generated_xF_y) The crystal defect is a damage defect, which may cause package bonding failure or cause bonding reliability reduction.

In order to reduce the crystal defects of the wafer products, the current main practice is to vacuum-pack the wafer products after the aluminum pad exposure process is completed, but temporarily unable to be shipped. However, the vacuum packaging process inevitably subjects the wafer to unpacking, repacking and other operations, which results in a large packaging material cost and labor cost for the wafer manufacturer. Moreover, the vacuum-packed wafer has a certain probability of suffering from air leakage caused by loose packing during the storage process, and the wafer may have crystallization defects after air leakage. For the wafers which are already delivered, the packaging manufacturer usually stores the wafers without unpacking, but the appearance quality problem of the wafers cannot be found in time. In addition, no matter the current vacuum storage mode of wafer production or the non-unpacking storage mode of packaging manufacturers, the wafer transmission boxes are independently and dispersedly stored, and the occupied site resources are serious.

In order to reduce the problem that the damage appears in wafer in the preservation process to reduce and avoid wafer product quality to be unusual or the condemned condition to appear even, the utility model provides a wafer storage device, figure 1 is the utility model discloses among the embodiment a cross section structure schematic diagram of wafer storage device, figure 2 is the utility model discloses among the embodiment a structural schematic diagram is overlooked to wafer storage device. As shown in fig. 1 and fig. 2, the wafer storage device according to the present embodiment includes:

the unit space 10 is used for storing a transmission box 11, and the transmission box 11 is used for bearing a plurality of wafers;

and a purging structure for gas-purging the unit space 10 to control the humidity inside the unit space 10.

In the embodiment, an independent and closed unit space 10 is provided for placing the transport box 11 that carries the wafer, and the unit space 10 is subjected to gas purging by a purging structure, so that water vapor, acidic gas (for example, fluorine-containing gas), particulate impurities, and the like in the unit space 10 can be timely discharged from the unit space 10, thereby ensuring that the humidity inside the unit space 10 is within a preset range, for example, controlling the humidity of the unit space 10 to be less than 5%, ensuring that a metal pad (for example, an aluminum pad) in the wafer located in the unit space 10 does not generate an electrochemical reaction, and further reducing or even avoiding the occurrence of crystallization defects on the wafer, so that the problem of quality reduction of the wafer in the storage process does not occur. Moreover, because the humidity in the unit space 10 is controlled by automatically purging the gas in the embodiment, and further the humidity in the conveying box 11 is controlled, the cost is low, and a large amount of packaging material cost and labor cost can be saved.

Optionally, the transfer BOX 11 is a Front Opening Unified BOX (FOUP) or a Front Opening Shipping BOX (FOSB).

The present embodiment is described by taking an example in which one transport box is disposed in one unit space 10 to avoid the mutual influence between different transport boxes. In other embodiments, in order to save storage cost, one skilled in the art can also place two or more transport boxes 11 in one of the unit spaces 10 according to actual needs.

Optionally, the number of the unit spaces 10 is plural;

a plurality of the unit spaces 10 are arranged in a three-dimensional array.

Specifically, in order to save space, the wafer storage apparatus may be provided with a plurality of unit spaces 10, and the plurality of unit spaces 10 may be arranged in a three-dimensional array. For example, as shown in fig. 1, the plurality of unit spaces 10 are not only arranged in parallel along the X-axis and Y-axis directions (the view shown in fig. 1 only shows that the plurality of unit spaces 10 are arranged in parallel along the X-axis direction, and not shown in parallel along the Y-axis direction), but also stacked along the Z-axis direction, thereby maximally utilizing space resources. The plurality described in this embodiment means two or more. The specific number and the specific arrangement of the unit spaces 10 can be set by those skilled in the art according to actual needs, for example, the number of the transfer boxes to be stored, the size of the field space for storage, and the like, which is not limited by the present embodiment.

Optionally, the number of the purging structures is multiple, and the plurality of purging structures correspond to the plurality of unit spaces 10 one to one.

Specifically, by providing the plurality of purging structures corresponding to the plurality of unit spaces 10 one to one, independent control of humidity in each unit space 10 can be achieved, and flexibility in use of the wafer storage device is improved.

Optionally, the purge structure includes:

an inlet duct 12 extending from the outside to the inside of the unit space 10 for delivering purge gas to the unit space 10;

and an outlet duct 13 extending from the inside of the unit space 10 to the outside for discharging the exhaust gas in the unit space 10.

Solid arrows in fig. 2 indicate a transfer path of the purge gas from the outside when transferred to the unit space 10, and dotted arrows indicate a transfer path of the exhaust gas from the inside of the unit space 10 when discharged to the outside. Specifically, a first main pipe 14 and a second main pipe 15 may be further provided for the wafer storage apparatus having a plurality of the unit spaces 10. The first main pipe 14 is communicated with a plurality of the air inlet pipes 12, and the purge gas is transmitted to each air inlet pipe 12 through the first main pipe 14. The second main pipe 15 is communicated with the plurality of outlet pipes 13, and the exhaust gas from each unit space 10 may be discharged to the outside through the second main pipe 15. The exhaust gas in this embodiment includes the purge gas, and moisture, acid gas (e.g., fluorine-containing gas), and the like in the unit space 10.

In this embodiment, the purge gas may be, but is not limited to, nitrogen or an inert gas. The inert gas in this embodiment means a gas formed from an element of group VIII of the periodic table.

Optionally, the purging structure further includes:

the one-way air inlet valve is arranged on the air inlet pipeline 12 and used for controlling whether the air inlet pipeline 12 is conducted or not;

and the one-way air outlet valve is arranged on the air outlet pipeline 13 and used for controlling whether the air outlet pipeline 13 is conducted or not.

Optionally, the purging structure further includes:

Specifically, by providing a one-way inlet valve on each of the inlet pipes 12 and a one-way outlet valve on each of the outlet pipes 13, and connecting the one-way inlet valve and the one-way outlet valve via the controller, it is possible to automatically control the purge gas to perform the gas purge on the single unit space 10 via the controller. Meanwhile, the controller controls the one-way air inlet valve and the one-way air outlet valve to be opened periodically, so that the quality of the wafer in the storage process can be ensured, and the storage cost is reduced. For example, the controller controls the one-way intake valve and the one-way exhaust valve to be opened every 30min to perform gas purging into the unit space 10. When the purge gas is nitrogen, the purge gas having a flow rate of 35L/min may be transferred to the unit space 10 for 6 to 10min after the one-way inlet valve and the one-way outlet valve are opened, thereby stabilizing the humidity within the unit space 10 to be 5% or less.

Optionally, the purging structure further includes:

and a sensor 20 disposed inside the unit space 10 for detecting humidity inside the unit space 10.

Optionally, the controller is connected to the sensor 20, and is configured to adjust the flow rate of the purge gas delivered to the unit space 10 according to the humidity inside the unit space 10 detected by the sensor 20.

Specifically, the sensor 20 is arranged to detect the humidity inside the unit space 10 in real time, so that not only can the humidity problem be found in time and the controller control the opening of the one-way air inlet valve and the one-way air outlet valve to save, but also the flow rate and the purging time of the purging gas can be adjusted in real time according to the humidity inside the unit space 10. For example, when the humidity inside the unit space 10 is relatively low, the flow rate of the purge gas and the purge time may be appropriately reduced; when the humidity inside the unit space 10 is relatively high, the flow rate of the purge gas and the purge time may be appropriately increased accordingly.

Optionally, the wafer storage device further includes:

and a buffer chamber 16 located outside the unit space 10, for receiving the transfer box 11 from the outside and adjusting the degree of vacuum inside the transfer box 11.

Specifically, after the pod 11 is transferred to the load port 17 of the wafer storage device, a transfer structure 18 (e.g., a robot) inside the wafer storage device transfers the pod to the buffer chamber 16. The buffer chamber 16 is used for adjusting the vacuum degree in the transfer box 11, so as to prevent the unit space 10 to be stored from being polluted due to the excessively low vacuum degree in the transfer box 11. Then, the transfer structure 18 transfers the transfer cassette after adjusting the degree of vacuum into one of the unit spaces 10. The transfer structure 18 is also used to take the pod out of one of the unit spaces 10 and transfer the pod to a load-out port 19, so as to transfer the pod to the outside of the wafer storage device.

The wafer storage device provided by the specific embodiment is provided with the unit space for storing the transmission box, and the purging structure is arranged to purge gas in the unit space, so that the control of the humidity in the unit space is realized, the problem of wafer damage caused by overlarge humidity in the unit space is avoided, the safety in the wafer storage process is improved, and the quality of wafer products is ensured.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A wafer storage device, comprising:

2. The wafer storage device according to claim 1, wherein the number of the unit spaces is plural;

the plurality of unit spaces are arranged in a three-dimensional array.

3. The wafer storage device as claimed in claim 2, wherein the number of the purge structures is plural, and the plural purge structures correspond to the plural unit spaces one to one.

4. The wafer storage device of claim 3, wherein the purge structure comprises:

5. The wafer storage device of claim 4, wherein the purge structure further comprises:

6. The wafer storage device of claim 5, wherein the purge structure further comprises:

7. The wafer storage device of claim 6, wherein the purge structure further comprises:

8. The wafer storage device as claimed in claim 7, wherein the controller is connected to the sensor for adjusting a flow rate of the purge gas delivered to the unit space according to the humidity inside the unit space detected by the sensor.

9. The wafer storage device of claim 1, further comprising:

10. The wafer storage device of claim 1, wherein the pod is a front opening wafer pod or a front opening shipping box.