CN1324647C - A method of sampling contamination inside a semiconductor wafer carrier - Google Patents

Abstract

The present invention discloses a method for sampling the internal contamination of a semiconductor wafer carrier. The method comprises placing a tool chamber in a clean room, then placing and fixing the semiconductor wafer carrier inside the tool chamber, and finally using at least one nozzle to evenly spray an extraction fluid onto the internal surface of the semiconductor wafer carrier and collect the extraction fluid.

Description

A method of sampling contamination inside a semiconductor wafer carrier

technical field

The invention provides a pollution sampling method inside a semiconductor wafer carrier, especially a pollution sampling method inside a 12-inch wafer transfer box (Front Opening Unified Pod, FOUP).

Background technique

Economy With the progress of the semiconductor industry technology and the consideration of economic benefits, the diameter of the wafer has also moved from 8 inches to 12 inches in the past. In order to reduce labor and enable safe, wear-free, and pollution-free transfer of wafers, the current 12-inch wafer factories generally use Front Opening Unfied Pod (FOUP) as the wafer carrier (wafer carrier), and the use of FOUP It not only saves the area of the clean room, but also can be used for temporary storage of chips, so it has the characteristics of operability and exchangeability.

Please refer to FIG. 1 , which is a schematic diagram of a conventional 12/8-inch wafer transfer box 10 . As shown in Figure 1, a 12/8 inch wafer transfer box 10 can be loaded with about 25 wafers 12, and a plurality of breathing filters (breathing filter) 14 are arranged on the side wall of the transfer box 10, and the main functions of the wafer transfer box 10 are as follows The wafer 12 is transported to each tool according to different manufacturing processes. Because the 12/8-inch wafer needs about 300 to 600 processes, such as photolithography process and ion implantation process, etc., it is very likely to cause chemical pollution on the inner wall of the transfer box 10 after the production is completed, and the chemical pollutants inside the transfer box 10 Can pollute the loaded wafer 12 again, and then produce the phenomenon of self-contamination (self-contamination), so the contamination situation in the transfer box 10 must be sampled and analyzed to grasp the self-contamination situation of the wafer and establish the relationship between the pollution degree and the product yield. relationship between.

The traditional 12-inch wafer transport box pollution sampling method directly injects deionized water into the transport box, soaks it for 24 hours and then takes it out for sampling analysis. However, the existing method does not establish a complete set of sampling procedures and sampling environment, which seriously affects the sampling accuracy and reliability of the results.

Contents of the invention

The main purpose of the present invention is to provide a method for sampling the internal contamination of semiconductor wafer carriers, which can solve the above-mentioned problems in the prior art.

According to the sampling method of the internal contamination of the semiconductor wafer carrier of the present invention, the method comprises a sampling method of the internal contamination of the semiconductor wafer carrier, the method comprises placing a tool chamber (toolchamber) in a clean room, and then placing the The semiconductor wafer carrier is placed and fixed inside the tool chamber, and finally at least one nozzle is used to uniformly spray the extraction fluid to the inner surface of the semiconductor wafer carrier and collect the extraction fluid.

The pollution sampling method of the semiconductor wafer carrier of the present invention first provides a clean room including a chemical filter device and a particle filter device, then places the cleaned and dried tool room in the clean room, and finally the semiconductor wafer carrier It is placed and fixed in the tool chamber, and a nozzle is used to evenly spray the extraction fluid to sample the contamination of the semiconductor wafer carrier. Compared with the pollution sampling method of the traditional semiconductor wafer carrier, the method of the present invention includes a complete sampling procedure and sampling environment, so the sampling result has higher accuracy and reliability.

Description of drawings

FIG. 1 is a schematic diagram of a conventional 12-inch wafer transfer box; and

2 to 3 are schematic diagrams of the pollution sampling method of the semiconductor wafer carrier of the present invention.

Wherein, the reference signs are explained as follows:

10 12-inch wafer transport box 12 wafers

14 Breathing filter 20 Clean room

22 fan 24 chemical filter

26 ultra-high performance filter 28 tool room

30 Bezel 3212/8-inch wafer transfer box

34 nozzle 36 slope

Detailed ways

The present invention provides a kind of sampling method of internal pollution of semiconductor wafer carrier, as shown in Figure 2, this method provides a clean room (clean room) 20, and clean room 20 comprises a fan 22, one is used for removing nitrogen oxides and A chemical filter screen 24 for sulfur oxides, and a boron free ultra-high performance filter screen (Ultra Low Penetration Air, UPLA) 26 for removing particles. Then a tool room 28 is placed in the clean room 20, the tool room 28 adopts an upper opening design, and the inner edge of the opening includes a baffle plate 30 with a width of about one centimeter, which is used to prevent the air in the clean room 20 from entering the tool room 28 and causing damage to the tool room 28. cause disturbance.

Then as shown in FIG. 3, a semiconductor wafer carrier (semiconductor wafer carrier), such as a 12-inch wafer transfer box (Front Opening Unified Pod, FOUP) 32, is placed in the tool room 28 with the opening facing down, and uses Four pillars (not shown) provided inside the tool room 28 fix the position of the FOUP 32 . Finally, a loop type nozzle (loop type) 34 is used to evenly spray the extraction fluid to the inner surface of the 12-inch wafer transfer box 32, and a slope 36 is formed below the tool chamber 28 and is arranged below the opening of the wafer transfer box 32 to collect the extraction fluid. Fluid and carry out qualitative and quantitative analysis of organic matter, inorganic matter or trace metal pollutants.

In order to make the extraction fluid evenly cover the inner surface of the wafer transport box 32, the nozzle 34 is designed as an annular nozzle and can rotate 360 degrees, and the pressure of each nozzle outlet is stable. At the same time, the method of the present invention can adjust the nozzle 34 rotating speed to improve extraction. Fluid coverage area. The extraction fluid includes deionized water and gases with high cleanliness such as helium and argon as carrier gas. The method of the present invention can control the amount of deionized water and carrier gas so that the extraction fluid presents a columnar or In addition, the method of the present invention can also control the temperature of the extraction fluid to increase the pollution sampling efficiency.

Before placing the 12-inch FOUP 32 in the tool chamber 28 for contamination sampling, the method of the present invention cleans and dries the tool chamber 28 to avoid affecting the contamination sampling result of the FOUP 32 . When carrying out the cleaning process of the tool chamber 28, utilize the nozzle 34 to evenly spray the deionized water and the hydrogen peroxide solution to the inside of the tool chamber 28, and when performing the drying procedure of the tool chamber 28, utilize the nozzle 34 to evenly spray the drying gas Tool room 28 interior.

In short, the sampling method for the internal contamination of the semiconductor wafer carrier of the present invention includes the following steps in sequence:

Provide a clean room;

Place a tool room in a clean room;

Carry out cleaning procedures for tool rooms;

carry out the drying procedure of the tool room;

Place and fix the 12-inch wafer transfer box inside the tool room;

Set the nozzle speed, temperature and type of extraction fluid (column or mist);

Continuously spray the extraction fluid evenly onto the inner surface of the 12-inch wafer transfer box by using the nozzle within a predetermined period of time; and

Collect the extraction fluid for contamination sampling and analysis.

The pollution sampling method of the semiconductor wafer carrier of the present invention first provides a clean room including a chemical filter device and a particle filter device, then places the cleaned and dried tool room in the clean room, and finally the semiconductor wafer carrier It is placed and fixed in the tool chamber, and a nozzle is used to evenly spray the extraction fluid to sample the contamination of the semiconductor wafer carrier. Compared with the pollution sampling method of the traditional semiconductor wafer carrier, the method of the present invention includes a complete sampling procedure and sampling environment, so the sampling result has higher accuracy and credibility.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (12)

1. A sampling method for internal contamination of a semiconductor wafer carrier, the method comprising: placing a tool room in a clean room that includes a chemical filter; placing and fixing the semiconductor wafer carrier inside the tool chamber with the opening facing downward; Utilizing at least one nozzle to uniformly spray extraction fluid onto the interior surface of the semiconductor wafer carrier according to the contaminants to be collected; and The extraction fluid is collected. 2. The pollution sampling method of claim 1, wherein the clean room further comprises a particulate filter. 3. The pollution sampling method according to claim 2, wherein the chemical filter device is used to remove nitrogen oxides and sulfur oxides. 4. The pollution sampling method according to claim 1, wherein the inner edge of the opening of the tool room includes a baffle plate for blocking the air in the clean room from entering the tool room. 5. The pollution sampling method of claim 1, wherein the nozzle is a ring nozzle. 6. The pollution sampling method of claim 1, wherein the extraction fluid comprises deionized water and a carrier gas. 7. The pollution sampling method according to claim 6, wherein the method comprises controlling the amount of deionized water and the amount of carrier gas in the extraction fluid so that the extraction fluid appears columnar or mist. 8. The contamination sampling method of claim 1, wherein the method includes controlling the temperature of the extraction fluid to increase contamination sampling efficiency. 9. The pollution sampling method of claim 1, wherein the semiconductor carrier includes a 12-inch wafer transfer box and an 8-inch wafer transfer box. 10. The contamination sampling method of claim 1, wherein prior to performing contamination sampling on the semiconductor wafer carrier, the method further comprises cleaning the tool chamber and drying the tool chamber. 11. The pollution sampling method according to claim 10, wherein the method utilizes the nozzle to evenly spray deionized water and hydrogen peroxide solution into the interior of the tool chamber to clean the tool chamber. 12. The pollution sampling method according to claim 10, wherein the method utilizes the nozzle to uniformly spray drying gas into the tool chamber to dry the tool chamber.

Images