A method for removing fluorine impurities from semiconductor surface

Abstract

The present invention provides a method for removing fluorine impurities from a semiconductor surface, the method comprising the following steps: (1) heating a semiconductor with fluorine impurities attached to the surface at 150°C-300°C under vacuum conditions, and placing activated carbon in the space where the semiconductor is located; (2) soaking the semiconductor treated in step (1) in an alkaline solution with a pH of not less than 9; (3) washing the semiconductor treated in step (2) with ethanol. The present invention provides a method for removing fluorine impurities from a semiconductor surface, the method of the present invention heats under vacuum conditions so that fluorine ions on the semiconductor surface can volatilize, and uses activated carbon to adsorb fluorine ions to prevent direct discharge into the air; the heating treatment can effectively remove fluorine impurities on the semiconductor surface, and further soaking in alkaline solution so that the fluorine on the semiconductor surface forms a salt precipitate, and further washing with ethanol further enhances the removal effect of fluorine impurities on the semiconductor surface.

Description

Technical Field

[0001] The invention relates to the field of semiconductor preparation technology, and in particular to a method for removing fluorine impurities from the surface of a semiconductor. Background Art

[0002] In recent years, affected by fierce international market competition and the impact of LED industry development, the competition in the semiconductor chip market has become fierce. As market competition continues to escalate, the chip market has gradually shifted from a competition dominated by product price competition to a competition pattern where product quality competition and price competition coexist. Product cost and product reliability have become the main criteria for measuring product competitiveness.

[0003] During the manufacturing process, fluorine impurities may remain on the surface of the semiconductor, affecting the performance of the product. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for removing fluorine impurities from the surface of a semiconductor.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a method for removing fluorine impurities from the surface of a semiconductor, the method comprising the following steps:

[0006] (1) A semiconductor with fluorine impurities attached to its surface is heated at 150°C-300°C under vacuum conditions, while activated carbon is placed in the space where the semiconductor is located;

[0007] (2) soaking the semiconductor treated in step (1) in an alkaline solution having a pH value of not less than 9;

[0008] (3) Clean the semiconductor after treatment in step (2) with ethanol.

[0009] The method of the present invention allows fluorine ions on the surface of the silicon wafer to volatilize by heating under vacuum conditions, and uses activated carbon to adsorb fluorine ions to prevent direct emission into the air; the heating treatment can effectively remove fluorine impurities on the surface of the semiconductor, and further immerse the semiconductor in alkaline solution to form salt precipitation of fluorine on the surface of the semiconductor, and further wash with ethanol to further enhance the removal effect of fluorine impurities on the surface of the semiconductor.

[0010] Preferably, the vacuum degree in step (1) is 300-400 Pa.

[0011] More preferably, the vacuum degree in step (1) is 350-400 Pa.

[0012] Preferably, the heating temperature in step (1) is 200-300°C.

[0013] Preferably, the heating treatment time in step (1) is 15-25 min.

[0014] Preferably, the soaking time in step (1) is 5-10 minutes.

[0015] Preferably, the washing temperature of ethanol in step (1) is 23°C to 25°C.

[0016] Preferably, the surface area of ​​the activated carbon is not less than 1000m 2 / g.

[0017] The beneficial effects of the present invention are as follows: the present invention provides a method for removing fluorine impurities from the surface of a semiconductor. The method of the present invention allows fluorine ions on the surface of the semiconductor to volatilize by heating under vacuum conditions, and uses activated carbon to adsorb fluorine ions to prevent direct discharge into the air; the fluorine impurities on the surface of the semiconductor can be effectively removed, and further by soaking in alkaline solution, the fluorine on the surface of the semiconductor forms a salt precipitate, and further by washing with ethanol, the removal effect of fluorine impurities on the surface of the semiconductor is further enhanced. DETAILED DESCRIPTION

[0018] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0019] Example 1

[0020] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the method comprises the following steps:

[0021] (1) A semiconductor with fluorine impurities attached to its surface is placed in a vacuum tube and activated carbon is placed at the end of the vacuum tube, the vacuum is evacuated to 300 Pa, and the tube is heated at 150° C. for 20 minutes; wherein the surface area of ​​the activated carbon is not less than 1000 m 2 / g;

[0022] (2) soaking the semiconductor treated in step (1) in an alkaline solution having a pH value of not less than 9 for 5-10 minutes;

[0023] (3) Clean the semiconductor after treatment in step (2) with ethanol at 23°C-25°C.

[0024] Example 2

[0025] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 1 is that the heating temperature in step (1) is 200°C.

[0026] Example 3

[0027] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 1 is that the heating temperature in step (1) is 300°C.

[0028] Example 4

[0029] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 1 is that the vacuum degree in step (1) is 350Pa.

[0030] Example 5

[0031] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 4 is that the heating temperature in step (1) is 200°C.

[0032] Example 6

[0033] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 4 is that the heating temperature in step (1) is 300°C.

[0034] Example 7

[0035] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 1 is that the vacuum degree in step (1) is 400 Pa.

[0036] Example 8

[0037] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 7 is that the heating temperature in step (1) is 200°C.

[0038] Example 9

[0039] As a method for removing fluorine impurities from a semiconductor surface according to an embodiment of the present invention, the only difference between this embodiment and Embodiment 7 is that the heating temperature in step (1) is 300°C.

[0040] Experimental Example 1

[0041] After applying the method for removing fluorine impurities from the semiconductor surface of Examples 1-9 of the present invention, the results of detecting the residual amount of fluorine impurities on the semiconductor surface are shown in Table 1.

[0042] Table 1 Removal effect of the method for removing fluorine impurities from the semiconductor surface

[0043] method Residue% Example 1 5-10％ Example 2 1-5％ Example 3 Below 1% Example 4 1-5％ Example 5 Below 1% Example 6 none Example 7 Below 1% Example 8 none Example 9 none

[0044] By comparing the results in Table 1, it is found that the higher the heating temperature and the higher the vacuum degree, the more conducive it is to the removal of fluorine impurities on the semiconductor surface. Taking all factors into consideration, the vacuum degree in step (1) is 350-400 Pa, and the heating temperature in step (1) is 200-300° C., which has a better effect on the removal of fluorine impurities on the semiconductor surface.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for removing fluorine impurities from a semiconductor surface, characterized in that: The method comprises the following steps: (1) A semiconductor with fluorine impurities attached to its surface is heated at 200°C-300°C under a vacuum condition of 350-400 Pa, and activated carbon is placed in the space where the semiconductor is located; (2) soaking the semiconductor treated in step (1) in an alkaline solution having a pH value of not less than 9; (3) Clean the semiconductor after treatment in step (2) with ethanol.

2. The method according to claim 1, characterized in that The heating time in step (1) is 15-25 minutes.

3. The method according to claim 1, characterized in that: The soaking time in step (1) is 5-10 minutes.

4. The method according to claim 1, characterized in that: The cleaning temperature of ethanol in step (1) is 23°C to 25°C.

5. The method according to claim 1, characterized in that The surface area of ​​the activated carbon is not less than 1000m 2 / g.