CN110739215A - Method for manufacturing SOI - Google Patents

Abstract

The invention provides a manufacturing method of SOI, comprising: oxidizing a first silicon wafer or a second silicon wafer to form an oxide layer on the first silicon wafer or the second silicon wafer; inside the silicon wafer or the second silicon wafer; attach the second silicon wafer to the first silicon wafer, and bond the first silicon wafer and the second silicon wafer to obtain a bonded wafer; anneal the bonded wafer, and the annealing temperature is the first temperature, and the annealing duration is the first duration; splitting the bonding sheet; polishing the split bonding sheet to a preset thickness to obtain SOI. In the SOI manufacturing method provided by the present invention, after the bonding sheet is split, the surface of the SOI is smoother, thereby reducing the polishing amount during mechanical polishing, and making the polished SOI film more uniform. Since the polishing amount during mechanical polishing is reduced, polishing time is saved, and the production efficiency of SOI is improved.

Description

Manufacturing method of SOI

technical field

The present invention relates to the technical field of SOI, in particular, to a manufacturing method of SOI.

Background technique

At present, with the continuous development of silicon material processing technology, people have paid more and more attention to the processing quality of wafers.

In the related art, when manufacturing SOI (Silicon-On-Insulator, silicon on insulating substrate), it is necessary to crack the bonding sheet by microwave. The surface of the SOI obtained after cracking is rough, and the surface layer has a damaged layer caused by hydrogen ion implantation. Therefore, the SOI surface must be mechanically polished, but the amount of polishing is large, and the uniformity of the film thickness is poor.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art or related technologies.

To this end, a first aspect of the present invention proposes a method for manufacturing an SOI.

In view of this, a first aspect of the present invention provides a method for manufacturing SOI, comprising: oxidizing a first silicon wafer or a second silicon wafer to form an oxide layer on the first silicon wafer or the second silicon wafer; It is divided into multiple injections into the first silicon wafer or the second silicon wafer; the second silicon wafer is attached to the first silicon wafer, and the first silicon wafer and the second silicon wafer are bonded to obtain a bonded wafer; The bonding sheet is annealed, the annealing temperature is the first temperature, and the annealing time is the first duration; the bonding sheet is split; and the split bonding sheet is polished to a preset thickness to obtain SOI.

In the SOI manufacturing method provided by the present invention, after the first silicon wafer or the second silicon wafer is oxidized, hydrogen ions are implanted into the first silicon wafer or the second silicon wafer for several times, so that the hydrogen ions are injected into the first silicon wafer. The distribution in the wafer or the second silicon wafer is more uniform. After the bonding wafer is split, the surface of the SOI is smoother, thereby reducing the polishing amount during mechanical polishing, so that the film of the polished SOI is more uniform. Since the polishing amount during mechanical polishing is reduced, polishing time is saved, and the production efficiency of SOI is improved. The hydrogen ions are implanted into the first silicon wafer or the second silicon wafer for several times, which reduces the energy and dose of hydrogen ions implanted in a single time, reduces the particles on the surface of the first silicon wafer or the second silicon wafer, and improves the first silicon wafer. The cleanliness of the silicon wafer or the second silicon wafer reduces defects in the SOI, thereby improving the quality of the SOI. Since the defects in the SOI are reduced, the qualified rate of the SOI product is improved, thereby reducing the production cost of the SOI.

In addition, the manufacturing method of SOI in the above-mentioned technical solutions provided by the present invention may also have the following additional technical features:

In the above technical solution, preferably, when the hydrogen ions are implanted into the first silicon wafer or the second silicon wafer in multiple times, the energy of the multiple implants is sequentially reduced, and the dose of the multiple implants is sequentially reduced.

In this technical solution, the energy and dose of multiple implantation are successively reduced, so that the hydrogen ions implanted into the first silicon wafer or the second silicon wafer are more uniform, and the quality of SOI is further improved.

In any of the above technical solutions, preferably, implanting hydrogen ions into the first silicon wafer or the second silicon wafer for multiple times includes: implanting hydrogen ions into the first silicon wafer or the second silicon wafer for the first time ; implanting hydrogen ions into the first silicon wafer or the second silicon wafer for the second time; implanting hydrogen ions into the first silicon wafer or the second silicon wafer for the third time.

In this technical solution, the hydrogen ions are implanted into the first silicon wafer or the second silicon wafer three times, which effectively improves the uniformity of hydrogen ions in the first silicon wafer or the second silicon wafer, and further improves the post-splitting efficiency. The surface quality of SOI reduces the amount of polishing during mechanical polishing, making the SOI film after polishing more uniform. In addition, the cleanliness of the first silicon wafer or the second silicon wafer is improved, defects in the SOI are reduced, and the quality of the SOI is improved.

In any of the above technical solutions, preferably, when hydrogen ions are implanted into the first silicon wafer or the second silicon wafer for the first time, the implantation energy is greater than or equal to 10Kev and less than or equal to 500Kev, and the implantation dose is greater than or equal to e ¹⁵ , and less than or equal to e ¹⁸ .

In this technical solution, when hydrogen ions are implanted for the first time, the implantation energy is greater than or equal to 10Kev (kiloelectron volts) to 500Kev, the implantation dose is greater than or equal to e ¹⁵ to e ¹⁸ , and the energy and dose of the second and third implantation It needs to be less than the energy and dose of the first injection.

In any of the above technical solutions, preferably, the first temperature is greater than or equal to 100°C and less than or equal to 350°C; the first duration is greater than or equal to 0.5h and less than or equal to 5h.

In this technical solution, annealing between 100°C and 350°C for 0.5h to 5h is low temperature annealing.

In any of the above technical solutions, preferably, splitting the bonding sheet includes: placing the bonding sheet into the chamber of the splitter; raising the temperature in the chamber to a third temperature for a third time period; controlling the microwave The magnetron head splits the bonding sheet.

In any of the above technical solutions, preferably, the third temperature is greater than or equal to 100° C. and less than or equal to 200° C.; the third time period is greater than or equal to 10 minutes and less than or equal to 30 minutes.

Preferably, the split time is 10 min.

Preferably, when the second silicon wafer is bonded to the first silicon wafer, the activation time is 0 to 200s.

Preferably, when the microwave magnetron head is controlled to split the bonding sheet, the microwave power of the microwave magnetron head ranges from 0 to 5000W.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows a flow chart of a manufacturing method of SOI according to an embodiment of the present invention;

FIG. 2 shows a schematic structural diagram of a first silicon wafer after oxidation according to an embodiment of the present invention;

FIG. 3 shows a schematic structural diagram after implanting hydrogen ions into the first silicon wafer according to an embodiment of the present invention;

FIG. 4 shows a schematic structural diagram of a bonding sheet according to an embodiment of the present invention;

FIG. 5 shows a schematic diagram of the structure after splitting according to an embodiment of the present invention;

FIG. 6 shows a flow chart of a manufacturing method of SOI according to another embodiment of the present invention;

FIG. 7 shows a flow chart of a manufacturing method of SOI according to still another embodiment of the present invention;

FIG. 8 shows a flow chart of a manufacturing method of SOI according to still another embodiment of the present invention;

FIG. 9 shows a flow chart of a manufacturing method of SOI according to still another embodiment of the present invention;

10 shows a flowchart of a method for manufacturing SOI according to yet another embodiment of the present invention;

Wherein, the corresponding relationship between the reference numerals and component names in Fig. 2 to Fig. 5 is:

1 first silicon wafer, 2 oxide layer, 3 hydrogen ions, 4 second silicon wafer.

Detailed ways

In order to understand the above objects, features and advantages of the present invention more clearly, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments may be combined with each other in the case of no conflict.

Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific details disclosed below. Example limitations.

The manufacturing method of the SOI according to some embodiments of the present invention will be described below with reference to FIGS. 1 to 10 .

In the embodiment of the first aspect of the present invention, as shown in FIG. 1 , the present invention provides a manufacturing method of SOI including:

Step 102 , as shown in FIG. 2 , oxidize the first silicon wafer 1 to form an oxide layer 2 on the first silicon wafer 1 ;

Step 104 , as shown in FIG. 3 , the hydrogen ions 3 are divided into multiple implants into the first silicon wafer 1 ;

Step 106, as shown in FIG. 4, attach the second silicon wafer 4 to the first silicon wafer 1, and bond the first silicon wafer 1 and the second silicon wafer 4 to obtain a bonding wafer;

Step 108, annealing the bonding sheet, the annealing temperature is the first temperature, and the annealing duration is the first duration;

Step 110, as shown in Figure 5, split the bonding sheet;

Step 112 , polishing the split bonding sheet to a preset thickness to obtain SOI.

In this embodiment, after the first silicon wafer 1 is oxidized, hydrogen ions 3 are implanted into the first silicon wafer 1 in multiple times, so that the distribution of hydrogen ions 3 in the first silicon wafer 1 is more uniform. After the slivers are combined, the surface of the SOI is smoother, thereby reducing the polishing amount during mechanical polishing, so that the film of the polished SOI is more uniform. Since the polishing amount during mechanical polishing is reduced, polishing time is saved, and the production efficiency of SOI is improved. The hydrogen ions 3 are implanted into the first silicon wafer 1 in multiple times, which reduces the energy and dose of a single implantation of the hydrogen ions 3, reduces the particles on the surface of the first silicon wafer 1, and improves the cleanliness of the first silicon wafer 1 , reducing the defects in the SOI, thereby improving the quality of the SOI. Since the defects in the SOI are reduced, the qualified rate of the SOI product is improved, thereby reducing the production cost of the SOI.

In one embodiment of the present invention, as shown in FIG. 6 , the manufacturing method of SOI includes:

Step 202, oxidizing the second silicon wafer 4 to form an oxide layer 2 on the second silicon wafer 4;

Step 204, the hydrogen ions 3 are divided into multiple implants into the first silicon wafer 1;

Step 206, bonding the second silicon wafer 4 to the first silicon wafer 1, and bonding the first silicon wafer 1 and the second silicon wafer 4 to obtain a bonding wafer;

Step 208, annealing the bonding sheet, the annealing temperature is the first temperature, and the annealing duration is the first duration;

Step 210, split the bonding sheet;

Step 212 , polishing the split bonding sheet to a preset thickness to obtain SOI.

In one embodiment of the present invention, as shown in FIG. 7 , the manufacturing method of SOI includes:

Step 302 , oxidize the first silicon wafer 1 to form an oxide layer 2 on the first silicon wafer 1 ;

Step 304, the hydrogen ions 3 are divided into multiple implants into the second silicon wafer 4;

Step 306, bonding the second silicon wafer 4 to the first silicon wafer 1, and bonding the first silicon wafer 1 and the second silicon wafer 4 to obtain a bonding wafer;

Step 308, annealing the bonding sheet, the annealing temperature is the first temperature, and the annealing duration is the first duration;

Step 310, split the bonding sheet;

Step 312 , polishing the split bonding sheet to a preset thickness to obtain SOI.

In one embodiment of the present invention, as shown in FIG. 8 , the manufacturing method of SOI includes:

Step 402 , oxidize the second silicon wafer 4 to form an oxide layer 2 on the second silicon wafer 4 ;

Step 404, the hydrogen ions 3 are divided into multiple implants into the second silicon wafer 4;

Step 406, bonding the second silicon wafer 4 to the first silicon wafer 1, and bonding the first silicon wafer 1 and the second silicon wafer 4 to obtain a bonding wafer;

Step 408, annealing the bonding sheet, the annealing temperature is the first temperature, and the annealing duration is the first duration;

Step 410, split the bonding sheet;

Step 412 , polishing the split bonding sheet to a preset thickness to obtain SOI.

Preferably, the implantation source is hydrogen or hydrogen helium or gas, and the ion implantation equipment is required to ensure that the implantation layer is covered with uniform hydrogen ions 3 .

In an embodiment of the present invention, preferably, when the hydrogen ions 3 are implanted into the first silicon wafer 1 in multiple times, the energy of the multiple implants decreases sequentially, and the dose of the multiple implants decreases sequentially.

In this embodiment, the energy and dose of multiple implants are sequentially reduced, so that the hydrogen ions 3 implanted into the first silicon wafer 1 are more uniform, and the quality of SOI is further improved.

In one embodiment of the present invention, as shown in FIG. 9 , the manufacturing method of SOI includes:

Step 502 , oxidize the first silicon wafer 1 to form an oxide layer 2 on the first silicon wafer 1 ;

Step 504, implanting hydrogen ions 3 into the first silicon wafer 1 for the first time;

Step 506, implanting hydrogen ions 3 into the first silicon wafer 1 for the second time;

Step 508, implanting hydrogen ions 3 into the first silicon wafer 1 for the third time;

Step 510, bonding the second silicon wafer 4 to the first silicon wafer 1, and bonding the first silicon wafer 1 and the second silicon wafer 4 to obtain a bonding wafer;

Step 512, annealing the bonding sheet, the annealing temperature is the first temperature, and the annealing duration is the first duration;

Step 514, split the bonding sheet;

Step 516, polishing the split bonding sheet to a preset thickness to obtain SOI.

In this embodiment, the hydrogen ions are injected into the first silicon wafer 1 in three times, which effectively improves the uniformity of the hydrogen ions 3 in the first silicon wafer 1, thereby improving the surface quality of the SOI after splitting, reducing the The small amount of polishing during mechanical polishing makes the SOI film after polishing more uniform. In addition, the cleanliness of the first silicon wafer 1 is improved, the defects in the SOI are reduced, and the quality of the SOI is further improved.

Preferably, hydrogen ions are implanted into the first silicon wafer 1 twice or four times.

In an embodiment of the present invention, preferably, when the hydrogen ions 3 are implanted into the first silicon wafer 1 for the first time, the implantation energy is greater than or equal to 10Kev and less than or equal to 500Kev, and the implantation dose is greater than or equal to e ¹⁵ and less than or equal to e ¹⁸ .

In this embodiment, when hydrogen ions 3 are implanted for the first time, the implantation energy is greater than or equal to 10Kev (kiloelectron volts) to 500Kev, the implantation dose is greater than or equal to e ¹⁵ to e ¹⁸ , and the energy of the second implant and the third implant is equal to The dose needs to be less than the energy and dose of the first injection.

In an embodiment of the present invention, preferably, the first temperature is greater than or equal to 100° C. and less than or equal to 350° C.; the first duration is greater than or equal to 0.5h and less than or equal to 5h.

In this embodiment, annealing between 100°C and 350°C for 0.5h to 5h is low temperature annealing.

In one embodiment of the present invention, as shown in FIG. 10 , the manufacturing method of SOI includes:

Step 602 , oxidize the first silicon wafer 1 to form an oxide layer 2 on the first silicon wafer 1 ;

Step 604, the hydrogen ions 3 are divided into multiple implants into the first silicon wafer 1;

Step 606, bonding the second silicon wafer 4 to the first silicon wafer 1, and bonding the first silicon wafer 1 and the second silicon wafer 4 to obtain a bonding wafer;

Step 608, annealing the bonding sheet, the annealing temperature is the first temperature, and the annealing duration is the first duration;

Step 610, putting the bonding sheet into the chamber of the splitter;

Step 612, raising the temperature in the chamber to a third temperature for a third time period;

Step 614, controlling the microwave magnetron head to split the bonding sheet;

Step 616 , polishing the split bonding sheet to a preset thickness to obtain SOI.

In an embodiment of the present invention, preferably, the third temperature is greater than or equal to 100° C. and less than or equal to 200° C.; the third time period is greater than or equal to 10 minutes and less than or equal to 30 minutes.

Preferably, the split time is 10 min.

Preferably, when the second silicon wafer 4 is bonded to the first silicon wafer 1, the activation time is 0 to 200s.

Preferably, when the microwave magnetron head is controlled to split the bonding sheet, the microwave power of the microwave magnetron head ranges from 0 to 5000W.

Compared with the traditional SOI manufacturing method provided by the SOI manufacturing method provided by the present invention, as shown in Tables 1 and 2, the number of particles on the surface of the SOI manufactured by using the SOI manufacturing method provided by the present invention is significantly reduced and uniform. Sex was significantly improved. Among them, Table 1 shows the particle number and uniformity of the SOI surface manufactured by the SOI manufacturing method provided by the present invention, and Table 2 shows the particle number and uniformity of the SOI surface manufactured by the traditional SOI manufacturing method.

film number 0.8 grains uniformity 1# 5 1.1% 2# 3 0.9% 3# 1 1.1% 4# 4 1.0% 5# 3 0.8% 6# 6 0.9% 7# 4 1.0% 8# 1 1.1% 9# 4 0.9% 10# 4 0.9%

Table I

film number 0.8 grains uniformity 1# 25 3.5% 2# 31 3.4% 3# 28 3.6% 4# 36 3.8% 5# twenty four 4.0% 6# 42 3.2% 7# 34 3.5% 8# 29 3.7% 9# 31 3.6% 10# 37 3.9%

Table II

In the description of the present invention, the term "plurality" refers to two or more than two, unless otherwise expressly defined, the orientation or positional relationship indicated by the terms "upper", "lower" etc. is based on the drawings. The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention; The terms "connected", "installed", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or through the middle media are indirectly connected. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the description of the present invention, the terms "one embodiment," "some embodiments," "a specific embodiment," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in the present invention. at least one embodiment or example of . In the present invention, schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. a manufacturing method of SOI, is characterized in that, comprises: oxidizing the first silicon wafer or the second silicon wafer to form an oxide layer on the first silicon wafer or the second silicon wafer; implanting hydrogen ions into the first silicon wafer or the second silicon wafer for multiple times; bonding the second silicon wafer to the first silicon wafer, and bonding the first silicon wafer and the second silicon wafer to obtain a bonding wafer; annealing the bonding sheet, the annealing temperature is the first temperature, and the annealing duration is the first duration; splitting the bonding sheet; The bond wafer after the split is polished to a preset thickness to obtain the SOI. 2. The manufacturing method of SOI according to claim 1, is characterized in that, When the hydrogen ions are implanted into the first silicon wafer in multiple times, the energy of the multiple implants decreases sequentially, and the dose of the multiple implants decreases sequentially. 3. The SOI manufacturing method according to claim 2, wherein the step of implanting hydrogen ions into the first silicon wafer or the second silicon wafer in multiple times comprises: implanting hydrogen ions into the first silicon wafer or the second silicon wafer for the first time; implanting hydrogen ions into the first silicon wafer or the second silicon wafer for the second time; The hydrogen ions are implanted into the first silicon wafer or the second silicon wafer for the third time. 4. The manufacturing method of SOI according to claim 3, is characterized in that, When hydrogen ions are implanted into the first silicon wafer or the second silicon wafer for the first time, the implantation energy is greater than or equal to 10Kev and less than or equal to 500Kev, and the implantation dose is greater than or equal to e ¹⁵ and less than or equal to e ¹⁸ . 5. The manufacturing method of SOI according to claim 1, is characterized in that, The first temperature is greater than or equal to 100°C and less than or equal to 350°C; The first duration is greater than or equal to 0.5h and less than or equal to 5h. 6. The manufacturing method of SOI according to any one of claims 1 to 5, characterized in that, splitting the bonding sheet comprises: putting the bonding sheet into the chamber of the splitter; increasing the temperature in the chamber to a third temperature for a third period of time; Control the microwave magnetron head to split the bonding sheet. 7. The manufacturing method of SOI according to claim 6, is characterized in that, The third temperature is greater than or equal to 100°C and less than or equal to 200°C; The third duration is greater than or equal to 10 minutes and less than or equal to 30 minutes.

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