WO2018145411A1

WO2018145411A1 - Method for fabricating inp thin film heterogeneous substrate

Info

Publication number: WO2018145411A1
Application number: PCT/CN2017/094038
Authority: WO
Inventors: 欧欣; 林家杰; 游天桂; 黄凯
Original assignee: 中国科学院上海微系统与信息技术研究所
Priority date: 2017-02-09
Filing date: 2017-07-24
Publication date: 2018-08-16
Also published as: CN106711026A

Abstract

Provided is a method for fabricating an InP thin film heterogeneous substrate, which at least comprises: providing an InP substrate, said InP substrate being provided with an implantation face (S1); performing ion co-implantation at the implantation face to form a defect layer at a preset depth of the InP substrate (S2); providing a heterogeneous substrate, and bonding the InP substrate with the heterogeneous substrate (S3), wherein the implantation face of the InP substrate is the bonding face; peeling a part of the InP substrate along the defect layer, such that a part of the InP substrate is transferred onto the heterogeneous substrate to form an InP thin film on the heterogeneous substrate, thereby obtaining an InP thin film heterogeneous substrate (S4). The above solution effectively reduces the dosage of single ion implantation required for peeling and transferring an InP thin film, and at the same time, avoids using the method of implanting at a below-zero low temperature in order to peel an InP material as discussed in prior art documents, thereby shortening a fabrication period and saving production cost. As low temperature or high temperature implantation is not needed, the additional energy consumption required for controlling implantation temperature may be reduced.

Description

Method for preparing InP film heterogeneous substrate

Technical field

The invention belongs to the technical field of semiconductor fabrication, and in particular relates to a method for preparing an InP film hetero-substrate by ion co-implantation.

Background technique

InP is a III-V compound semiconductor with wide band gap, fast electron mobility, high thermal conductivity and good radiation resistance. InP devices can amplify high-frequency or short-wavelength signals, combined with its high radiation resistance, are often used to make satellite signal receivers and amplifiers. The wide band gap makes the device highly stable and is affected by the outside world. Smaller. In terms of optoelectronic integrated circuits, InP is the only monolithic integrated semiconductor material that can support a single light source. InP is a direct bandgap semiconductor that can be made into optical amplifiers, lasers and photodetectors. In addition, InP can provide nanoseconds. The modulation speed of the stage can also realize the shunting and aggregation of power, as well as the multiplexing of passive optical waveguides and wavelengths. The optoelectronic integrated circuits made by the advantages of InP have excellent performance in complex communication systems.

As semiconductor chips become more integrated, the integration of InP on heterogeneous substrates is also particularly important. At present, the implementation of InP heterogeneous integrated materials mainly uses heteroepitaxial growth methods such as MBE, MOCVD and the like. However, heteroepitaxially grown InP heterogeneous materials have problems such as reverse phase domain, lattice mismatch and thermal expansion coefficient, which make it have larger defect density than InP single crystal material, which reduces the performance of the device. reliability. In addition, InP substrates are very expensive, which results in the inability to use InP materials on a large scale. In order to overcome these shortcomings, a new method for preparing InP film heterogeneous integrated materials has emerged - ion beam stripping, that is, ion implantation of a certain amount of energy into the InP substrate, and a defect layer is generated at a predetermined depth of the substrate, The ion-implanted substrate is bonded to the foreign substrate, and finally, after annealing at a certain temperature, the InP film is peeled off from the InP substrate along the defect layer, thereby transferring the InP film onto the foreign substrate. The InP thin film heterogeneous integrated material obtained by the ion implantation stripping method can well eliminate the defects caused by the lattice mismatch and overcome the problems faced by the heteroepitaxial growth; in addition, the stripped InP substrate can be recycled. , reducing costs.

However, the ion implant stripping method has been reported to produce InP thin film heterogeneous integrated materials mostly under special temperature window conditions, such as low temperature below 0 °C or high temperature above 150 °C, or H alone. Controlling the injection temperature requires additional energy consumption, the process is complicated, and the surface of the sample is easily foamed during the high temperature injection process, which is not conducive to the subsequent bonding process. In addition, the critical dose of the implanted ions required to separately implant the H or He stripped InP film is also compared. High, high dose ion implantation creates a thicker damage layer in the transferred film, which has a large effect on the crystal quality of the InP film.

Therefore, there is an urgent need to develop a technique for preparing an InP thin film heterogeneous integrated material by low-dose ion implantation and stripping at room temperature.

Summary of the invention

In view of the above disadvantages of the prior art, an object of the present invention is to provide a method for preparing an InP film hetero-substrate for solving the low-temperature or high-temperature implantation of an InP film hetero-substrate in the prior art. The problem of high injection dose required.

To achieve the above and other related objects, the present invention provides a method for preparing an InP film hetero-substrate, characterized in that the preparation method comprises at least:

S1: providing an InP substrate, and the InP substrate has an implantation surface;

S2: performing ion implantation on the implantation surface to form a defect layer at a predetermined depth of the InP substrate;

S3: providing a heterogeneous substrate, bonding the InP substrate to the heterogeneous substrate, the injection surface of the InP substrate being a bonding surface;

S4: stripping a portion of the InP substrate along the defect layer, transferring a portion of the InP substrate onto the foreign substrate, to form an InP film on the foreign substrate, and obtaining an InP film different Substrate.

As a preferred embodiment of the present invention, in step S2, the ions implanted in the implant toward the InP substrate are H ions and He ions.

As a preferred embodiment of the present invention, the order of ion co-implantation of the implant toward the InP substrate is:

He ions are implanted first, then H ions are implanted; or H ions are implanted first, then He ions are implanted; or H ions and He ions are simultaneously implanted.

As a preferred embodiment of the present invention, the implantation dose of the H ions is 1E16 cm ^-2 to 1E17 cm ^-2 , and the implantation dose of the He ions is 1E16 cm ^-2 to 1E17 cm ^-2 .

As a preferred embodiment of the present invention, the implantation depth of the He ions is the same as or similar to the implantation depth of the H ions.

As a preferred embodiment of the present invention, in the step S2, the depth of the defect layer formed in the ion-implanted InP substrate is 10 nm to 10 μm.

As a preferred embodiment of the present invention, in the step S2, the temperature of the InP substrate is maintained at -100 ° C to 100 ° C during the ion implantation.

As a preferred embodiment of the present invention, in the step S3, the heterogeneous substrate is any one of silicon, silicon dioxide, sapphire, silicon carbide, diamond, gallium nitride, gallium arsenide or glass.

As a preferred embodiment of the present invention, in the step S3, the bonding method is any one of direct bonding, growth medium layer (such as SiO2) bonding, polymer bonding, and spin-on glass bonding.

As a preferred embodiment of the present invention, in step S3, at least the ion implantation is performed before bonding. The process of annealing the InP substrate, wherein the annealing temperature is less than 150 °C.

As a preferred embodiment of the present invention, in step S4, the structure obtained in step S3 is annealed to peel off a portion of the InP substrate along the defect layer to obtain the InP thin film foreign substrate.

As a preferred embodiment of the present invention, the annealing treatment is performed by annealing at a first temperature and then annealing at a second temperature, wherein the first temperature is lower than the second temperature.

As a preferred embodiment of the present invention, the first temperature is 50 ° C to 200 ° C; and the second temperature is 200 ° C to 400 ° C.

As a preferred embodiment of the present invention, the annealing time is performed at the first temperature for 1 h to 10 h; and the annealing is performed at the second temperature for 1 min to 240 min.

As described above, the method for preparing an InP film hetero-substrate of the present invention has the following beneficial effects:

1) effectively reducing the ion implantation dose required for peeling and transferring the InP film, thereby shortening the preparation cycle and saving the production cost; meanwhile, the method can also solve the problem that some materials cannot be peeled off by using a single ion implantation;

2) Reduce the critical dose of ions implanted during the ion implantation process, alleviate the damage generated when transferring the InP film, and improve the quality of the InP film.

3) No low temperature or high temperature injection is required, thereby reducing the additional energy consumption required to control the injection temperature, preventing bubble formation on the surface of the sample during high temperature injection, and facilitating subsequent bonding.

DRAWINGS

1 is a flow chart showing a method of preparing an InP thin film hetero substrate provided by the present invention.

2 to FIG. 5 are schematic diagrams showing the structures corresponding to the steps of the method for preparing an InP thin film hetero substrate provided by the present invention.

Component label description

1 InP substrate

11 injection surface

12 defect layer

13 InP film

14 InP substrate residual material

2 heterogeneous substrate

3 InP film heterogeneous substrate

detailed description

The embodiments of the present invention are described below by way of specific examples, and those skilled in the art can readily understand other advantages and effects of the present invention from the disclosure of the present disclosure. The present invention may be embodied or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

Please refer to Figure 1 to Figure 5. It should be noted that the illustrations provided in the embodiments merely illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the drawings, rather than the number and shape of components in actual implementation. Dimensional drawing, the actual type of each component's type, number and proportion can be a random change, and its component layout form may be more complicated.

Referring to FIG. 1 , the present invention provides a method for preparing an InP film heterogeneous substrate, the method comprising at least:

S4: stripping a portion of the InP substrate along the defect layer, transferring a portion of the InP substrate onto the foreign substrate, to form an InP film on the hetero-substrate, and obtaining an InP film different Substrate.

The preparation method of the InP thin film composite substrate of the present invention will be described in detail below with reference to the specific drawings.

Referring to S1 and FIG. 2 in FIG. 1, step S1 is performed to provide an InP substrate 1, and the InP substrate has an implantation surface 11;

Specifically, the InP substrate 1 has an upper surface and a lower surface, and both can be used as the injection surface 11. In the embodiment, the upper surface is selected as the injection surface 11. In addition, the InP substrate may be a single crystal or a polycrystalline structure. In the embodiment, the InP substrate 1 is a commercially available InP single crystal wafer.

Referring to S2 and FIG. 3 in FIG. 1, step S2 is performed, ion implantation is performed on the implantation surface 11, and a defect layer 12 is formed at a predetermined depth of the InP substrate 1;

Specifically, according to the requirement of actually preparing the InP film hetero-substrate, a predetermined depth is defined in the InP substrate 1. When ions are implanted from the injection surface, the energy of the ion implantation is sufficient to enable the implanted ions to reach the pre-injection. A depth is set and the defect layer 12 is formed at the predetermined depth.

As an example, in step S2, the ions co-implanted into the InP substrate 1 on the implantation surface 11 are H ions and He ions.

Specifically, the ion species of the ion implantation may be other kinds of ions that can achieve the same or similar functions, and are not limited herein.

As an example, the order of co-implanting the InP substrate 1 on the implantation surface 11 is: first implanting He ions, Re-inject H ions; or inject H ions first, then inject He ions; or simultaneously inject H ions and He ions.

As an example, the implantation dose of the H ions is 1E16 cm ^-2 to 1E17 cm ^-2 , and the implantation dose of the He ions is 1E16 cm ^-2 to 1E17 cm ^-2 .

Specifically, in an embodiment, He ions may be implanted first, and the He ions may form defects in the lattice formation at the peeling depth (ie, at the defect layer 12), and the defects are present in the defect layer 12 Gaussian distribution; re-injection of H ions, which can be trapped by the platform defects formed by He ions and physically expand and combine these platform-type defects, eventually forming cracks that can separate the InP substrate, thereby promoting part of the InP substrate Peeling is achieved from the point where the defect concentration is the largest. Among them, the defect layer formed by the first implanted He can effectively capture the H implanted later, and avoid the effect of peeling off the InP due to the too wide distribution of the implant H.

Further, in the process of ion implantation, He ions enter the atomic gap to form micro defects, and in the subsequent processing, these micro defects will aggregate and combine to form a platform type defect; after the H ions are implanted into the InP substrate, A defect is generated, the H ions are trapped in the defect and a pressure is generated, and in the subsequent process, part of the InP substrate can be peeled off from the maximum defect concentration. When two ions are co-implanted, He ions are used to form defects as described above, and the defects are Gaussian in the defect layer 12; H ions can be trapped by the platform defects formed by He ions and physically act on These platform-type defects are expanded and combined with each other to finally form cracks that can separate the InP substrate, thereby facilitating the partial peeling of the InP substrate from the maximum defect concentration. Co-implantation of H ions and He ions is performed in the InP substrate 1, and H ions can be trapped by defects formed by He ions, and then enter the atomic gap and apply pressure, which is equivalent to the inside of the defects generated by He ions. An additional force can effectively promote the peeling of the InP substrate 1 at a low ion implantation dose, that is, the total dose of ion implantation can be effectively reduced, thereby shortening the preparation cycle and saving the production cost. The ion implantation dose is preferably H 2E16cm ^{^-2} ~ 7E16cm ^-2, the He ion implantation dose is preferably 1E16cm ^{^-2} ~ 5E16cm ^-2. In the present embodiment, the implantation dose of the H ions is preferably 3E16 cm ^-2 , and the implantation dose of the He ions is preferably 2E16 cm ^-2 .

As an example, the implantation depth of the He ions is the same as or similar to the implantation depth of the H ions.

Specifically, in the ion implantation process, the energy of the implanted ions can be adjusted so that the implantation depths of the two ions are the same. That is, the energy of the implanted ions corresponds to the ion implantation depth (that is, the depth of the defect layer 12 described in this embodiment, that is, the thickness of the InP film 13 expected in the present embodiment), and the injected The larger the ion energy, the deeper the defect layer 12 is formed, and the thicker the InP film 13 is obtained by subsequent peeling, and the shallower the defect layer 12 is formed, the thinner the subsequent peeling of the InP film 13 is.

Further, the implantation depth of the He ion is the same as the implantation depth of the H ion, and the range (Rp) of the He ion can be ensured in the vicinity of the range of the H ion implantation to promote subsequent peeling, of course, in order to realize this function. Next, the implantation depth of the He ions and the implantation depth of the H ions may be close to each other.

As an example, in step S2, the depth of the defect layer 12 formed by ion implantation into the InP substrate 1 is 10 nm to 10 μm.

Specifically, the distance between the defect layer 12 formed by implanting ions and the injection surface 11 is 10 nm to 10 μm. Preferably, the depth of the defect layer 12 is 11 nm to 9 μm. In the embodiment, the defect Layer 12 has a depth of 1 μm.

As an example, in the step S2, the temperature of the InP substrate 1 is maintained at -100 ° C to 100 ° C during the ion implantation.

Specifically, during the ion implantation process, the InP substrate 1 is maintained at -100 ° C to 100 ° C. At this time, the implanted ion concentration is Gaussian in the InP substrate 1 and is in the substrate material. A crystal defect is introduced to form the defect layer 12. Preferably, the holding temperature of the InP substrate 1 is -100 ° C to -55 ° C or 0 ° C to 45 ° C or 90 ° C to 100 ° C. In the present embodiment, the holding temperature of the InP substrate 1 is room temperature. . At this temperature, it is not necessary to peel off like a conventional InP film, and it needs to be in a specific temperature window (high temperature or low temperature). This application uses hydrogen and helium co-injection to reduce the total injection dose required for peeling, which can be conveniently It is carried out at room temperature, and the additional energy consumption required to control the injection temperature is reduced, and the phenomenon that the surface of the sample has been foamed during the high temperature injection process is alleviated, which is favorable for the subsequent bonding process.

It should be noted that since the two ions co-injection change the force of the substrate to peel off, the dose of the required implanted ions is reduced, and the external conditions of the defect distribution during ion implantation are also changed, and the control of the condition is controlled. The aspect is derived from the energy generated by ion implantation, and on the other hand, it is provided by the outside. Therefore, this reduces the energy consumption required for controlling the external temperature, and further alleviates the phenomenon that the surface of the sample has been foamed during the high temperature injection process. Conducive to the subsequent bonding process.

Referring to S3 and FIG. 4 in FIG. 1 , step S3 is performed to provide a hetero-substrate 2, and the InP substrate is bonded to the hetero-substrate 2, and the implantation surface 11 of the InP substrate is Bonding surface

As an example, in step S3, the foreign substrate 2 is any one of silicon, silicon dioxide, sapphire, silicon carbide, diamond, gallium nitride, gallium arsenide or glass.

As an example, in the step S3, the bonding method is any one of direct bonding, growth medium layer (such as SiO ₂ ) bonding, polymer bonding, and spin-on glass bonding.

Specifically, in other embodiments, other bonding modes that achieve the same function and achieve the same effect may also be used, and are not limited herein. By the above bonding method, the defect can be controlled within a very small thickness range near the interface, so that the internal lattice quality of the film is not affected, and the injection surface 11 and one surface of the foreign substrate 2 are firmly fixed. Bond.

As an example, in step S3, at least a process of annealing the ion-implanted InP substrate is further performed before bonding.

Specifically, the InP substrate or the process of annealing the InP substrate and the hetero-substrate may be performed before bonding, and the annealing is preferably a low-temperature annealing to perform the surface of the substrate Defect repair, secure bond bonding structure. The annealing is a low temperature annealing to ensure that the annealing temperature is less than the temperature at which the surface begins to foam due to heating (generally less than 150 degrees).

Referring to S4 and FIG. 5 in FIG. 1 , step S4 is performed to peel off a portion of the InP substrate 1 along the defect layer 12, and transfer a portion of the InP substrate 1 to the foreign substrate 2, To form an InP film 13 on the hetero-substrate, an InP film hetero-substrate 3 is obtained.

As an example, in step S4, the structure obtained in step S3 is annealed to peel off portions of the InP substrate 1 (ie, InP substrate residual material 14) along the defect layer 12 to obtain the InP film heterogeneous liner. Bottom 3.

As an example, the annealing treatment is performed by annealing at a first temperature and then annealing at a second temperature, wherein the first temperature is lower than the second temperature.

As an example, the first temperature is from 50 ° C to 200 ° C; and the second temperature is from 200 ° C to 400 ° C.

As an example, the annealing time at the first temperature is 1 h to 10 h; the annealing time at the second temperature is 1 min to 240 min.

Specifically, the annealing is performed for a long time at a lower temperature (such as the first temperature), so that the H ions and the He ions have sufficient migration energy to form defects, that is, to promote H or He in the material. Diffusion and bonding with defects in the material, but ensuring that a large amount of said H ions and said He ions are not escaped from said InP substrate; and further at a higher temperature (such as said second temperature) Annealing is performed to cause defects in the formed defect layer 12 to be tangled in a defect band, so that peeling occurs. Among them, during the annealing process, the aggregation of H and/or He is thermally expanded, increasing the pressure inside the defect, causing the breakage of chemical bonds and the increase of defects, forming a platform-type defect (defective band) at the defect layer, and ultimately leading to Peeling of InP film. Therefore, the composite annealing process combined with the low temperature pre-annealing and the high temperature post-annealing can shorten the annealing time more than the direct annealing process. In addition, the annealing process preferably forms at least one gas in a vacuum environment or in a nitrogen gas and an inert gas. Under the protective atmosphere.

Specifically, the first temperature is preferably from 80 ° C to 150 ° C; the second temperature is preferably from 210 ° C to 240 ° C; the annealing treatment is preferably performed at the first temperature for a period of 1 h to 4 h; The annealing treatment is preferably performed at the second temperature for a period of from 1 min to 60 min. In this embodiment, the first temperature is 100 ° C, the second temperature is 220 ° C, the annealing treatment is performed at the first temperature for 2 h, and the annealing treatment is performed in the first The annealing time at two temperatures was 30 min.

It should be noted that after transferring the InP film 13 to the foreign substrate 2, the InP substrate residual material 14 can be recycled after being processed, for example, as the InP substrate 1 in FIG.

In summary, the present invention provides a method for preparing an InP film hetero-substrate, the preparation method comprising at least: providing an InP substrate, wherein the InP substrate has an implantation surface; and performing ion implantation on the injection surface Injecting and forming a defect layer at a predetermined depth of the InP substrate; providing a foreign substrate, bonding the implanted surface to the foreign substrate; The trap layer peels off the portion of the InP substrate, transferring a portion of the InP substrate onto the foreign substrate to form an InP film on the hetero-substrate to obtain an InP film hetero-substrate. Through the above scheme, the common ion implantation can effectively reduce the ion implantation dose required for peeling and transferring the InP film, thereby shortening the preparation cycle and saving the production cost; meanwhile, the method can also solve the use of a single ion for some materials. Injecting can not achieve the problem of peeling; reduce the critical dose of implanted ions during ion implantation, alleviate the damage caused by transferring InP film, improve the quality of InP film; prepare the InP film hetero-substrate by ion implantation stripping technology, no low temperature Or high temperature injection, which reduces the additional energy required to control the injection temperature, and places bubbles on the surface of the sample during high temperature injection to facilitate subsequent bonding.

The above-described embodiments are merely illustrative of the principles of the invention and its effects, and are not intended to limit the invention. Modifications or variations of the above-described embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and scope of the invention will be covered by the appended claims.

Claims

A method for preparing an InP film heterogeneous substrate, characterized in that the preparation method comprises at least:

S1: providing an InP substrate, and the InP substrate has an implantation surface;

S2: performing ion implantation on the implantation surface to form a defect layer at a predetermined depth of the InP substrate;

S3: providing a heterogeneous substrate, bonding the InP substrate to the heterogeneous substrate, the injection surface of the InP substrate being a bonding surface;

S4: stripping a portion of the InP substrate along the defect layer, transferring a portion of the InP substrate onto the foreign substrate, to form an InP film on the hetero-substrate, and obtaining an InP film different Substrate.
The method of preparing an InP thin film hetero-substrate according to claim 1, wherein in the step S2, the ions implanted in the injection toward the InP substrate are H ions and He ions.
The method for preparing an InP thin film hetero-substrate according to claim 2, wherein the order of ion implantation by the implant facing the InP substrate is:

He ions are implanted first, then H ions are implanted; or H ions are implanted first, then He ions are implanted; or H ions and He ions are simultaneously implanted.
The method for preparing an InP film heterogeneous substrate according to claim 2, wherein the implantation dose of the H ions is 1E16 cm -2 to 1E17 cm -2 , and the implantation dose of the He ions is 1E16 cm -2 to 1E17 cm. -2 .
The method for producing an InP thin film foreign substrate according to any one of claims 2 to 4, wherein the implantation depth of the He ions is the same as or similar to the implantation depth of the H ions.
The method of producing an InP thin film foreign substrate according to claim 1, wherein in the step S2, the depth of the defect layer formed by ion implantation into the InP substrate is 10 nm to 10 μm.
The method of preparing an InP thin film foreign substrate according to claim 1, wherein in the step S2, the temperature of the InP substrate is maintained at -100 ° C to 100 ° C during the ion implantation.
The method for preparing an InP thin film hetero substrate according to claim 1, wherein in the step S3, the heterogeneous substrate is silicon, silicon dioxide, sapphire, silicon carbide, diamond, gallium nitride, arsenic. Any one of gallium or glass Kind.
The method for preparing an InP film heterogeneous substrate according to claim 1, wherein in the step S3, the bonding method is direct bonding, growth medium layer bonding, polymer bonding, spin coating glass bonding. Any of the combinations.
The method for preparing an InP film hetero-substrate according to claim 1, wherein in the step S3, at least the process of annealing the ion-implanted InP substrate is further performed before bonding, wherein The annealing temperature is less than 150 °C.
The method for preparing an InP thin film hetero-substrate according to claim 1, wherein in step S4, the structure obtained in step S3 is annealed to peel off a portion of the InP substrate along the defect layer, The InP film heterogeneous substrate is obtained.
The method for preparing an InP thin film hetero-substrate according to claim 11, wherein the annealing is performed by annealing at a first temperature and then annealing at a second temperature, wherein the first The temperature is lower than the second temperature.
The method of preparing an InP thin film foreign substrate according to claim 12, wherein the first temperature is 50 ° C to 200 ° C; and the second temperature is 200 ° C to 400 ° C.
The method for preparing an InP thin film hetero-substrate according to claim 13, wherein the annealing is performed at the first temperature for 1 h to 10 h; and the annealing at the second temperature is 1 min. ~240min.