阅读说明：本技术 晶圆传送盒 (Wafer transfer box ) 是由 陈肖 于 2021-07-29 设计创作，主要内容包括：本发明提供了一种晶圆传送盒,包括：一侧设置有开口的盒体、对称设置在所述开口两侧的侧壁的卡槽及设置在与所述开口相对的后壁上的气敏传感单元,以监控晶圆传送盒内设定气体的浓度变化情况。本发明利用气敏传感单元监控晶圆传送盒内设定气体的浓度变化情况。此外,可以通过所述设定气体的浓度变化情况分析晶圆进行离子注入工艺后析出离子的浓度,从而实现对晶圆离子注入工艺的注入浓度的侧面监控。(The invention provides a wafer transfer box, comprising: one side of the wafer conveying box is provided with an open box body, clamping grooves symmetrically arranged on the side walls of the two sides of the opening and a gas-sensitive sensing unit arranged on the rear wall opposite to the opening so as to monitor the concentration change condition of set gas in the wafer conveying box. The invention utilizes the gas sensitive sensing unit to monitor the concentration change condition of the set gas in the wafer transfer box. In addition, the concentration of ions precipitated after the wafer is subjected to the ion implantation process can be analyzed through the concentration change condition of the set gas, so that the lateral monitoring of the implantation concentration of the wafer ion implantation process is realized.)

1. A wafer transport cassette, comprising: one side of the wafer conveying box is provided with an open box body, clamping grooves symmetrically arranged on the side walls of the two sides of the opening and a gas-sensitive sensing unit arranged on the rear wall opposite to the opening so as to monitor the concentration change condition of set gas in the wafer conveying box.

2. The wafer transport box of claim 1, wherein the gas sensor unit comprises a plurality of semiconductor gas sensors uniformly arranged in a vertical direction, and the arrangement direction of the semiconductor gas sensors in the vertical direction is perpendicular to the extending direction of the card slot on the side wall.

3. The wafer transport box of claim 2, wherein one semiconductor gas sensor corresponds to a plurality of slots for monitoring the concentration variation of the set gas in the area of the plurality of slots.

4. The wafer transport box of claim 3, wherein the vertical length of the semiconductor gas sensors is greater than or equal to the height of the region of the card slot.

5. The foup of claim 3, wherein the semiconductor gas sensor comprises a thin film type gas sensor comprising an N-type semiconductor thin film sensor or a P-type semiconductor thin film sensor.

6. The wafer conveying box as claimed in claim 2, wherein an indicator lamp is disposed on an outer wall of the box body, and the indicator lamp is connected to the gas sensing unit.

7. The wafer conveying box as claimed in claim 6, wherein the number of the indicator lamps is the same as the number of the semiconductor gas sensors, and the indicator lamps are correspondingly connected with the semiconductor gas sensors.

8. The wafer conveying box as claimed in claim 1, wherein an alarm system is disposed on an outer wall of the box body, and the alarm system is connected to the gas sensing unit.

9. The transport pod as claimed in claim 1 wherein the pod is configured to transport wafers after an ion implantation process.

10. The transport pod as claimed in claim 9, wherein the set gas is generated by reaction of ions deposited from the wafer with a surface material of the wafer.

11. The foup of claim 1 or 9, wherein the set gas comprises ammonia.

Technical Field

The invention relates to the technical field of integrated circuit manufacturing, in particular to a wafer transfer box.

Background

At present, wafers are protected, transported and stored mainly by means of a front Opening Unified pod (foup) in a wafer intelligent production process, so as to protect the wafers in the wafer transfer box, prevent the wafers from being polluted by dust in the external environment during the transfer process, and improve the yield of products.

In the production of large integrated circuit wafers, ION Implantation (IMP) is required to implant different types of IONs at different energies into different regions at different depths on the wafer in order to achieve or improve device performance. However, the IMP process has a problem of doped ion deposition, and since the wafer is stored in the closed wafer transport box after the IMP process is completed, the deposited doped ions are collected in the wafer transport box and associated with the surface of the waferThe surface material reacts to form defects, for example, when the waiting time (Q time) after IMP process is too long, the wafer may precipitate fluorine ions (F)^-) Ammonium fluoride (NH) which reacts with the surface material of the wafer to form white or colorless leaf crystals₄F) Defects, or generation of volatile gaseous ammonia (NH) gas with strong oxidizing properties₃) The specific chemical reaction formula is as follows:

F^-+NH4⁺→NH₄F+heat→(NH₄)HF₂+NH₃

at present, the conventional defect monitoring method mainly monitors the by-products through optical scanning, however, the method cannot monitor invisible gas by-products, and for ammonium fluoride and other by-products which can continue to react to generate invisible gas, the existing defect monitoring method also has the problem of monitoring timeliness, and cannot effectively monitor the defects of the ion implantation process.

Disclosure of Invention

The invention aims to provide a wafer transmission box, which monitors the concentration change condition of set gas in the wafer transmission box through a gas-sensitive sensing unit.

In order to achieve the above object, the present invention provides a wafer pod, comprising: one side of the wafer conveying box is provided with an open box body, clamping grooves symmetrically arranged on the side walls of the two sides of the opening and a gas-sensitive sensing unit arranged on the rear wall opposite to the opening so as to monitor the concentration change condition of set gas in the wafer conveying box.

Optionally, the gas-sensitive sensing unit includes a plurality of semiconductor gas-sensitive sensors uniformly arranged in the vertical direction, and the arrangement direction of the semiconductor gas-sensitive sensors in the vertical direction is perpendicular to the extending direction of the clamping groove on the side wall.

Optionally, one semiconductor gas sensor corresponds to a plurality of the slots to monitor the concentration change of the set gas in the area where the plurality of slots are located.

Optionally, the length of the vertical arrangement of the semiconductor gas sensors is greater than or equal to the height of the region where the card slot is located.

Optionally, the semiconductor gas sensor includes a thin film type gas sensor, and the thin film type gas sensor includes an N-type semiconductor thin film sensor or a P-type semiconductor thin film sensor.

Optionally, an indicator light is arranged on the outer wall of the box body, and the indicator light is connected with the gas-sensitive sensing unit.

Optionally, the number of the indicator lamps is the same as that of the semiconductor gas sensors in the gas sensor unit, and the indicator lamps are correspondingly connected with the semiconductor gas sensors.

Optionally, an alarm system is arranged on the outer wall of the box body, and the alarm system is connected with the gas-sensitive sensing unit.

Optionally, the wafer transfer box is used for transferring a wafer after an ion implantation process is performed.

Optionally, the set gas is generated after ions precipitated from the wafer react with a surface material of the wafer.

Optionally, the setting gas comprises ammonia.

In summary, the present invention provides a wafer transfer box, comprising: one side of the wafer conveying box is provided with an open box body, clamping grooves symmetrically arranged on the side walls of the two sides of the opening and a gas-sensitive sensing unit arranged on the rear wall opposite to the opening so as to monitor the concentration change condition of set gas in the wafer conveying box. The invention utilizes the gas sensitive sensing unit to monitor the concentration change condition of the set gas in the wafer transfer box. In addition, the concentration of ions precipitated after the wafer is subjected to the ion implantation process can be analyzed through the concentration change condition of the set gas, so that the lateral monitoring of the implantation concentration of the wafer ion implantation process is realized.

Drawings

Fig. 1 is a schematic perspective view of a wafer pod according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the FOUP of FIG. 1 taken along direction AB;

FIG. 3 is a schematic diagram illustrating an abnormal concentration of ions or gases in a portion of a wafer transfer box according to an embodiment of the present invention;

wherein the reference numbers are as follows:

1-box body; 11-opening; 12-a gas sensitive sensing unit; 121-semiconductor gas sensor; 13-a card slot;

2-a box cover; 3-wafer.

Detailed Description

The following describes in more detail embodiments of the present invention with reference to the schematic drawings. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Fig. 1 is a schematic perspective view of a wafer pod according to an embodiment of the present invention; fig. 2 is a schematic cross-sectional view of the foup of fig. 1 taken along direction AB. Referring to fig. 1 and 2, the wafer transport box of the present embodiment includes a box body 1 having an opening 11 at one side, card slots 13 symmetrically disposed on the sidewalls of the opening 11, and a gas-sensitive sensing unit 12 disposed on the rear wall opposite to the opening 11 to monitor the concentration change of the set gas in the wafer transport box.

Referring to fig. 2, a box cover 2 is further disposed at the opening 11 of the box body 1 and is matched with the opening 11, so that a closed space is formed in the wafer transfer box, and the wafer 3 in the wafer transfer box is prevented from being contaminated. In this embodiment, the foup can load twenty-five wafers at a time (that is, the wafer carrying capacity of the foup is 25), and in other embodiments of the present invention, the wafer carrying capacity of the foup can be adjusted according to actual needs, which is not limited by the present invention.

In this embodiment, the gas sensing unit 12 includes five semiconductor gas sensors 121 uniformly arranged in a vertical direction, the arrangement direction of the semiconductor gas sensors 121 in the vertical direction is perpendicular to the extending direction of the card slots 13 on the side wall, and one semiconductor gas sensor 121 corresponds to a plurality of card slots 13, so as to monitor the concentration change condition of the set gas in the area where the plurality of card slots 13 are located (which is equivalent to monitoring the concentration change condition of the set gas around the wafer 3 placed on the plurality of card slots 13). In other embodiments of the present invention, the number of the semiconductor gas sensors 121 included in the gas sensing unit 12 may be several, for example, the number of the semiconductor gas sensors 121 included in the gas sensing unit 12 may be adjusted to one, two, or ten, and the arrangement manner of the semiconductor gas sensors 121 may be adjusted according to actual needs, which is not limited in this invention. Preferably, the length of the vertical arrangement of the semiconductor gas sensors 121 (i.e., the length indicated by a in fig. 2) is greater than or equal to the height of the region where the card slot 13 is located (i.e., the height indicated by b in fig. 2), so as to ensure that the monitoring range of the gas sensor unit 12 covers all the wafers 3 in the box 1.

In this embodiment, the wafer transport box is used to transport the wafer 3 after the ion implantation process, and the set gas is generated after the ions precipitated from the wafer 3 react with the surface material 3 of the wafer. Optionally, the setting gas includes ammonia, and the semiconductor gas sensor 121 is configured to monitor a concentration change of the ammonia in the cartridge 1. Specifically, after the ion implantation process is performed on the wafer 3, the wafer 3 is stored in the wafer transfer box, and the box cover 2 covers the opening 11 of the box body 1, so that a closed environment is formed in the wafer transfer box. Since the ion implantation process has a problem of doped ion deposition, the wafer 3 may deposit ions, so that the ion concentration in the wafer transfer box is changed.

Illustratively, if the ion implantation process of the wafer 3 is performed with an excessively high concentration of fluorine ions (F)^-) Or the wafer 3 is left standing in the wafer transfer box for too long (Q time) after the ion implantation process, fluorine ions are precipitated from the wafer 3, and the precipitated fluorine ions react with the surface material of the wafer 3 to generate white or colorless leaf-shaped crystal ammonium fluoride (NH)₄F) Defects, or generation of volatile gaseous ammonia (NH) gas with strong oxidizing properties₃) The specific chemical reaction formula is as follows:

F^-+NH4⁺→NH₄F+heat→(NH₄)HF₂+NH₃

in the present embodiment, the semiconductor gas sensor 121 includes a thin film type gas sensor including an N-type semiconductor thin film sensor or a P-type semiconductor thin film sensor. Since ammonia gas has strong oxidizing property and contacts with a semiconductor film in the semiconductor gas sensor 121 and undergoes an oxidation-reduction reaction, so as to change the resistivity of the semiconductor film, the change of the concentration of ammonia gas in the wafer transfer box can be obtained by monitoring the change of the resistivity of the semiconductor gas sensor 121, and the change of the concentration of fluorine ions precipitated from the wafer 3 can be obtained.

When the semiconductor gas sensor is an N-type semiconductor thin film sensor, the contact of ammonia gas and the N-type semiconductor thin film can cause the reduction of carriers, so that the resistivity of the N-type semiconductor thin film sensor is increased; when the semiconductor gas sensor is a P-type semiconductor thin film sensor, the contact of ammonia gas and the P-type semiconductor thin film can cause the increase of carriers, so that the resistivity of the P-type semiconductor thin film sensor is reduced. In other embodiments of the present invention, when the type of the implanted ions in the ion implantation process is changed, the byproduct (including the setting gas) generated after the reaction between the extracted ions and the surface material of the wafer 3 is also changed accordingly, so that the corresponding gas sensor can be replaced according to the types of the extracted ions and the byproduct.

Based on this, a concentration threshold and a resistivity threshold can be set in combination with existing data to determine whether the ion or gas concentration in the pod is abnormal. Taking the N-type semiconductor thin film sensor as an example, setting the concentration value of ammonia gas in the wafer transmission box when the ammonium fluoride defect appears on the surface of the wafer as a concentration threshold, and setting the resistivity of the semiconductor gas sensor in the wafer transmission box when the concentration of ammonia gas is the concentration threshold as a resistivity threshold; when the resistivity of the semiconductor gas sensor is larger than or equal to the resistivity threshold, the concentration of ammonia gas in the wafer transfer box is larger than or equal to the concentration threshold (namely, the concentration of ions or gas in the wafer transfer box is abnormal), which indicates that ammonium fluoride defects may exist on the surface of the wafer, or the wafer is implanted with over-high concentration fluorine ions in the ion implantation process.

Correspondingly, an indicator light (not shown in the figure) is further arranged on the outer wall of the box body 1, and the indicator light is connected with the gas-sensitive sensing unit 12. When the concentration of the set gas in the wafer transfer box is abnormal, the gas-sensitive sensing unit 12 sends an electric signal to the indicator light, and the indicator light is lightened. Preferably, the number of the indicator lamps is the same as that of the semiconductor gas sensors 121 in the gas sensor unit 12, and the indicator lamps are correspondingly connected to the semiconductor gas sensors 121. Referring to fig. 3, when the ion or gas concentration in only a partial region (i.e., the region indicated by X in fig. 3) of the foup is abnormal, the semiconductor gas sensor in the gas sensor unit 12 responsible for monitoring the corresponding region sends an electrical signal to the indicator lamp connected thereto and causes the corresponding indicator lamp to light up. The method can visually display the area with abnormal ion or gas concentration in the wafer transmission box, and is convenient for positioning the wafer with surface defects or the wafer with abnormal ion implantation concentration.

Optionally, an alarm system (not shown in the figure) is further disposed on the outer wall of the box body 1, and the alarm system is connected to the gas-sensitive sensing unit 12. When the concentration of gas or ions in the wafer transfer box is abnormal, the gas-sensitive sensing unit 12 sends an electric signal to the alarm system, and the signal sending unit gives an alarm after receiving the electric signal, so that the lateral monitoring of the injection concentration of the wafer ion injection process is realized, and whether the surface defect exists in the wafer transfer box or whether the injection concentration of the wafer ion injection process is too high is judged.

In summary, the present invention provides a wafer transfer box, comprising: one side of the wafer conveying box is provided with an open box body, clamping grooves symmetrically arranged on the side walls of the two sides of the opening and a gas-sensitive sensing unit arranged on the rear wall opposite to the opening so as to monitor the concentration change condition of set gas in the wafer conveying box. The invention utilizes the gas sensitive sensing unit to monitor the concentration change condition of the set gas in the wafer transfer box. In addition, the concentration of ions precipitated after the wafer is subjected to the ion implantation process can be analyzed through the concentration change condition of the set gas, so that the lateral monitoring of the implantation concentration of the wafer ion implantation process is realized.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any way. It will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.