TW200414417A - Recycling a wafer comprising a buffer layer, after having taken off a thin layer therefrom - Google Patents

Abstract

Method of recycling a donor wafer (10) after taking off at least one useful layer, the donor wafer (10) comprising successively a substrate (1), a buffer structure (I) and, before taking-off, a useful layer. The method comprises removal of substance relating to part of the donor wafer (10) on the side where the taking-off took place, such that, after removal of substance, there remains at least part of the buffer structure (I) capable of being reused as at least part of a buffer structure (I) during a subsequent taking-off of a useful layer. The present document also relates to: - a method of producing a donor wafer (10) which can be recycled according to the invention; - methods of taking a thin layer off a donor wafer (10) which can be recycled according to the invention; - donor wafers (10) which can be recycled according to the invention.

Description

200414417 A7 B7 V. Description of the invention (1) [Technical field to which the invention belongs] • The present invention relates to a donor wafer including a buffer layer after transferring a thin semiconductor layer from a donor wafer to a receiving substrate. Of recycling. 5 [Prior art] The term " buffer layer " usually refers to a transition layer between, for example, a first crystal structure and a second crystal structure of a substrate, the second crystal structure having properties that modify the material (such as structure or stoichiometry Characteristics, or atomic surface recombination characteristics). 10 In the special case of the buffer layer, the latter makes it possible to obtain a second crystal structure, and its lattice parameters are substantially different from those of the substrate. For this Purpose, the buffer layer may have a composition that gradually changes with the thickness, and then the gradual change of the composition of the buffer layer is directly related to its gradually changing lattice tea number. 15 It may also have a more complex pattern (for example, it may have a variable The change in the composition of the rate, the sign of the rate is reversed, or the discontinuous jump in the composition), this type may be completed using a layer of a fixed composition containing defects. Next, mention metamorphic (slow For example, in the case of perturbation) or deterioration, the consumer co-operatives of the Intellectual Property Bureau of the Ministry of Economic Affairs printed, for example, metamorphic epitaxy. One layer or a superimposed layer generated on the buffer layer can be removed from the donor wafer to be transferred to the receiving substrate. One of the main applications for transferring the thin layer formed on the buffer layer is the formation of a strained silicon layer. If the lattice parameters in the interface plane of a layer are larger or smaller than the paper size of the specimen, the Chinese National Standard (CNS) A4 (210 x 297 mm) applies. 200414417 A7 B7 V. Description of the invention (2) If the lattice parameter is called, This layer is made of a material that stretches or compresses "strain". Otherwise, if the "relaxed" material is substantially close to the nominal lattice parameter of a layer, 'this layer can be said to be composed of a "relaxed" material, where the nominal lattice number 5 is the material in its equilibrium state Lattice parameters of the overall form. When a layer is composed of tensile strained slab, it can significantly improve certain characteristics such as the electron mobility of materials. Other materials such as SiGe can also be substantially similarly removed. Then, especially by a process called Smart-cut @, which is familiar to those skilled in the art 10, this layer is transferred onto the receiving substrate, so that a structure such as SOI (silicon on the insulating layer) is produced. The structure becomes possible. For example, the structure obtained after removing a relaxed SiGe layer can then be used as a support for silicon growth. Because the nominal lattice parameter (depending on the germanium content) of SiGe is larger than that of silicon 15 Nominal lattice parameters, so the obtained SGOI (SiGe on insulation layer) pseudo substrate • The growth of silicon on the silicon layer makes it possible to provide a silicon layer with tensile strain. For example, an example of this process is described in the IBM literature by L. J. Huang et al. ("Insulation layers prepared by wafer bonding and layer transfer for high-performance field-effect transistors" SiGe (SiGe-On-Insulator prepared 20 by wafer bonding and layer transfer for high-performance field-effect transistors) ", Applied Physics Letters, February 26, 2001, Volume 78, No. 9), in Among them are methods for manufacturing Si / SG〇I structures. Another example of such a process is described in document US 2002/007481. -4- _______ _ This paper size applies the Chinese National Standard (CNS) A4 regulations (210 x 297 public love) 200414417 A7 B7 V. Description of the invention (3) Other applications of metamorphic growth are possible, especially with regard to the Π-ν family Half • Conductor. Therefore, transistors are generally manufactured by using a technique based on GaAs or InP. 5 In terms of electronic performance, InP has substantial advantages over GaAs. In particular, the combination of the InP layer and the InGaAs or InAlAs layer allows us to improve electron mobility. However, in the face of GaAs technology, the ability to sell components using InP technology is limited, especially in terms of cost, availability, mechanical weakness, and the size of the main substrate 10 board (compared to the 6-inch diameter of GaAs, the largest InP The diameter is generally 4 inches). With reference to the receiving substrate, the InP layer removed and obtained through the metamorphic epitaxy of the buffer layer on the GaAs substrate seems to have found a solution to this problem. 15 Then, some removal processes, such as “etchback” type processes, will cause the substrate and buffer residues to be destroyed during the removal period. In some other removal processes, such as the Smart-cut © process, the substrate can be recycled, but the buffer layer can be lost. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs However, the technology of deterioration production is complicated. 20 Therefore, fully utilizing and producing such a buffer layer may require a lengthy, difficult and expensive operation. Furthermore, internal strains caused by changes in the composition may cause high-rate occurrences of crystal defects such as misalignment and point defects. In particular, by increasing the thickness, the paper size of these internal strains and thus defects can be applied to the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 V. Description of the invention (4) Minimize production and lattice Parameters change with thickness. • The buffer layer is usually made thick for this reason, and the thickness typically ranges from 1 to several micrometers (// m). However, economic and technical constraints limit certain basic characteristics of the buffer layer, such as its thickness or some structural complexity. For all these reasons, it would be wise to completely avoid the formation of a buffer layer after each substrate recovery. [Summary of the Invention] According to a first embodiment aspect, the present invention intends to achieve this by providing a method for recovering a donor wafer after removing at least one useful layer of 10 materials selected from a semiconductor material, the donor wafer sequentially The method includes removing a substrate, a buffer structure, and a useful layer before removal. The method includes removing a substance on a side of a donor wafer from which the removal is performed. The method is characterized in that after removing the material, at least a part of the buffer structure will be removed. Residual, at least a portion of this buffer structure can then be reused as a buffer structure for later useful layer removal. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs In a preferred embodiment of the recycling method according to the present invention, the protective layer is further present in the donor wafer, so that at least a portion of the buffer structure can be located below it; The material of the layer is selected from the crystalline material to use the method of removing the substance by 20 to have an etching ability, so that the selective removal of the substance can be manipulated, wherein the etching ability is for the material of the protective layer and at least one of the two adjacent zones. The materials are essentially different. According to the second embodiment, the present invention provides a method for generating donor wafers. According to the preferred recycling method, the donor wafers are intended to provide for removal by -6- this paper size is applicable to China National Standard (CNS) A4 specifications (210 x297 mm) 200414417 A7 B7 5. Description of the invention (5) and useful layers that can be recovered after removal, are characterized by the following steps:--forming the first part of the buffer structure on the substrate;-in the buffer structure A protective layer made of a material selected from crystalline materials is formed on the first part; 5-A second part of the buffer structure is formed on the protective layer so that it has a lattice parameter near the protective layer, the lattice parameter It is substantially the same as the lattice parameter of the first part of the buffer structure near the protective layer. According to a third embodiment, the present invention provides a method for removing a useful layer on a donor wafer so as to be transferred to a receiving substrate, which is characterized in that it comprises: (a) bonding the donor wafer to the receiving substrate; (b) bonding The useful layer of the receiving substrate is separated from the donor wafer, and (c) the donor wafer is recovered according to the recovery method. According to a fourth aspect, the present invention provides a method for periodically removing useful layers from a donor wafer, which is characterized in that it includes several steps 15 of removing useful layers, each of which follows the removal method. According to a fifth embodiment, the present invention provides the periodic removal method or an application of the removal method for generating a structure including a receiving substrate and a useful layer, the useful layer including at least one of the following materials: an employee of the Intellectual Property Bureau of the Ministry of Economic Affairs Consumption Cooperation

SiGe, Si, and III-V alloys are selected from the possible combinations of 20 (Al, Ga, In)-(N, P, As), respectively. According to a sixth embodiment, the present invention provides a donor wafer conforming to the methods according to the present invention. Other implementation aspects, purposes, and advantages of the present invention will be read through the operation of its preferred methods, and provided through non-limiting examples and made with reference to the following details. -7- This paper size applies to Chinese National Standards (CNS) A4 specification (210 x 297 mm) 200414417 A7 B7 V. Description of invention (6) Detailed explanation makes it clearer. [Embodiment] The main object of the present invention is to recover a wafer containing a buffer structure (that is, any structure that acts as a buffer layer) after at least one useful layer has been removed from the wafer, so that This useful layer is integrated into the semiconductor structure, and the recovery includes at least a partial restoration action of the buffer structure, which can make it reused in subsequent removal. Therefore, the reclamation action must include proper processing that does not damage at least a part of the buffer structure. 10 Indeed, buffer structures often include, for example, crystallographic defaults that are misplaced, and when supplied with energy, they can grow and increase in size in an important way, which can be heat treated, chemically processed, or mechanically processed. To provide. For example, 'If the siGe is heated at 350 ° C, 450 ° C, or 550 ° C, the buffer structure of the Intellectual Property Bureau of the Ministry of Economic Affairs, the consumer cooperation, and the printing of the 15th structure will change the structure state relative to the selected temperature • (See, for example, the literature by Re et al. "Structural characterisation and stability of Sil-xGex / Si (100 (Growth of Sil-xGex / Si (100) heterostructures grown by molecular beam epitaxy") ) heterostructures grown by molecular beam epitaxy ", 20 July 2001, Journal of Crystal Growth, vols. 227-228, pp. 749-755). As the temperature increases, the cushioning structure will tend to reduce its internal stress by mitigating them by using sliding surfaces, stacking defects, or other structural relaxation patterns. This will cause some difficulties in the future at the interface with the useful layer to be formed. Then, it is important to maintain these internal stresses in the buffer structure. -8- Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, 200414417 A7 B7 V. Description of the Invention (7) Next, the recovery and collection must be achieved by a method suitable for recycling, so as to avoid and limit the internal structure of the buffer structure. The extension of these crystalline stresses can damage their characteristics and thus the characteristics of useful layers formed thereon. 5 Advantageously, the cushioning structure has a crystal structure that is substantially loose and / or the number of structural defects on the surface is not noticeable. In this document, the "π buffer layer" has been more widely defined as above. Advantageously, the buffer layer is included in the buffer structure and has at least one of the following two functions: 10 1. Reduce defects in the upper layer Density; 2. Match one lattice parameter of two crystalline structures with different lattice parameters. Regarding the second function of the buffer layer, the buffer layer is an interlayer between the two structures, and the buffer layer is at it One of the surfaces has a first lattice parameter that is substantially the same as the lattice parameter of the first configuration, and has 15 second surfaces around a second crystal that is substantially the same as the lattice parameter of the second configuration In the rest of this document, the buffer layer or structure described will generally follow this latter buffer layer. However, the present invention also relates to any buffer layer defined in this document in the most general way. Or any buffer structure. Furthermore, an example of the method according to the present invention will be described below, which includes recovering a donor wafer of a useful layer by removal, the donor wafer is initially composed of a support substrate A buffer structure formed. Referring to FIG 1, comprising the conventional known technologies 1〇 donor wafer (by the present paper is suitable China National Standard Scale (CNS) A4 size (210x297 mm)

200414417 A7 B7 V. Description of the invention (0 removed a thin layer of donor) is composed of a support substrate 1 and a buffer structure I. The application of this donor wafer 10 in the present invention is from the part 4 of the buffer structure I and / or at least a part of the overlayer 5 (not shown in the figure) formed on the surface of the buffer structure I 1) The useful layer is removed in order to integrate it into a structure such as an SOI structure. The support substrate 1 of the donor wafer 10 includes at least one semiconductor layer having a first lattice parameter, which is located at the interface between the support substrate 1 and the buffer structure I. In a special configuration, the support substrate 1 is composed of a single semiconductor having a first lattice parameter 10. In the first configuration of the buffer structure I, the buffer structure I is composed of a 'buffer layer 2'. In this case, the buffer layer 2 on the support substrate 1 may cause a second lattice 15 parameter on the surface thereof that is substantially different from the first lattice parameter of the substrate 1, so that it may have the same donor wafer 10 in the same donor wafer 10. The two layers 1 and 4 have different lattice parameters. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economics Furthermore, in some applications, the buffer layer 2 may make it possible for the overlying layer to avoid high defect densities and / or receive significant stress. 20 Furthermore, in some applications, the buffer layer 2 may make it possible for the upper cover layer to have a good surface condition. In general, the buffer layer 2 has a lattice parameter that gradually changes with thickness in order to establish a transition between the two lattice parameters. This layer is commonly referred to as the metamorphic layer. -10- This paper size applies to China National Standard (CNS) A4 specification (210 X 297 mm) 200414417 A7 B7 V. Description of the invention (9) The gradual change of this lattice parameter may be continuous within the thickness of the buffer layer 2. produce. Alternatively, it may be implemented in "stages". Each stage is a thin layer with substantially fixed crystal lattice parameters that are different from the lattice parameters of the next stage. Change the lattice parameters separately. It can also have more complex forms, such as changes in a composition with a variable rate, inversion of the sign of the rate, or discrete jumps in the composition. It is preferable to detect the change in the lattice parameter of the buffer layer 2 in a gradual manner starting from the substrate 1 by increasing the concentration of at least one atomic element not contained in the substrate 1. Therefore, for example, the buffer layer 2 produced on the substrate 1 composed of the earlier material may be composed of a binary, ternary, quaternary or higher material. Therefore, for example, the buffer layer 2 generated on the substrate 1 made of a binary material 15 may be made of a ternary, quaternary, or higher material. It is best to use the CVD and MBE technologies ("Chemical Vapour Deposition" & "Molecular Beam Epitaxy" &"; (Abbreviation of) is produced by growing on the support substrate 1 (for example by epitaxy). 20 In general, the buffer layer 2 may be produced by any other known method in order to obtain, for example, by Buffer layer 2 composed of various alloys of different atomic elements. The secondary step of trimming the surface of substrate 1 under buffer layer 2 (such as by CMP polishing) may occur before manufacturing buffer layer 2. -11 -This paper size applies to China National Standard (CNS) A4 (210x297 mm) 200414417 A7 B7 V. Description of the invention (10) In the second configuration of buffer structure I, and referring to Figure 1, buffer structure I A buffer layer 2 (substantially the same as the buffer layer of the first configuration) and an additional layer 4. The additional layer 4 may be between the substrate 1 and the buffer layer 2, or on the buffer layer 25, such as Figure 1. In the first In particular cases, such an additional layer 4 may constitute a second buffer layer, for example, a buffer layer which makes it possible to limit defects, thereby improving the crystal quality of one layer generated on the buffer structure I. This additional layer 4 is composed of It is preferably composed of a semiconductor 10 having a fixed material composition. Then, the selection of the composition and thickness of the buffer layer 4 to be produced is a particularly important criterion for achieving such characteristics. Therefore, for example, stupidity The structural defects in the crystal growth layer usually gradually decrease within the thickness of this layer. 15 In the second special case, the additional layer 4 is located on the buffer layer 2 and acts as the upper layer of the buffer layer 2. Therefore, it can fix the second layer Lattice parameters. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. In the third special case, the additional layer 4 is located on the buffer layer 2 and plays a role in the removal action to be implemented in the donor wafer 10. Extraction of its levels. The additional layer can also have several functions, such as those selected from the last three special cases. In an advantageous configuration, the additional layer 4 is located at the buffer layer 2 And has a second lattice parameter that is different from the first lattice parameter of the supporting substrate 1. -12- This paper size applies to the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 V. Description of the invention ( 11) In the special case of this latter configuration, the additional layer 4 is composed of a material that is relaxed by the buffer layer 2 and has a second lattice lattice number. The additional layer 4 is preferably made of CVD or MBE. Resulting from the growth on the buffer layer 2 (for example, by epitaxial growth). 5 In the first embodiment, the growth of the additional layer 4 is in place and is directly continued from the formation of the buffer layer 2 below it, In this case, the buffer layer 2 is also preferably formed by layer growth. In the second embodiment, the growth of the additional layer 4 is achieved after a minor step of trimming the surface of the underlying buffer layer 2 (for example, by CMP polishing, heat treatment, or other 10 leveling techniques), so as to be included in the buffer layer 2 Misalignment and other defects will not grow, will not increase in size, and will not create any sliding surfaces, stacking defects, or other defects that will reduce the quality of the final buffer structure I formed thereby. The removal of useful layers from the donor wafer 10 operates according to one of the following main modes: (1) The useful layers to be removed are part of the additional layer 4. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs (2) The useful layer to be removed is part of the upper cover layer (not shown in Figure 1). The upper cover layer may have been trimmed before the surface of the buffer structure I is trimmed. For example, it is formed in advance on the buffer structure I by epitaxial growth. 20 Next, the donor wafer 10 is used as a substrate for the growth of the upper cover layer. Depending on the desired removal mode, the upper cover layer may contain one or more thin layers. Furthermore, it is preferable to have a loose surface substantially free from the cushion structure I. 13- This paper size applies the Chinese National Standard (CNS) A4 specification (210 x 297 mm) 10 15 This 200414417 A7 invention description (12 other The lattice parameters of the material are the same, such as the same layer, or all or some of the crystalline structure with its tensile or compressive strain, or a combination of these two types of materials. In the special embodiment of the donor wafer 10, one or more interlayers will be further inserted between the buffer structure! And the upper cover layer. In this case, this or these interlayers will not be (3) Useful layers to be removed are additional layer 4 and an upper layer

(Formed in substantially the same manner as described in the second extraction mode for the supply type A). Regardless of the selected removal mode 'and referring to Fig. 2, after the removal and in the case of a large number of nights, the protruding portion 7a and / or the crude sugar portion will almost appear on the removal surface of the remaining donor wafer 10. This removal surface "表面" belongs to layer 7 after removal on the surface of __2. According to the removal mode selected from the three previously discussed removal modes, the layer 7 after removal is all or all of layer 4 Some may be composed of one or more interlayers and may be part of the upper cover layer. The portions 7 a and 7 b that appear clearly on the surface of the layer 7 after removal are mainly based on the removal mode and the removal period. The operation mode depends on the operation method. The removal mode used in the IJJL project is not to remove the useful layer on the entire surface of the donor wafer, but to remove only a part of the donor wafer (usually There is a layer on top of it) so that, for example, those protruding parts on the surface of the donor body 10 indicated by reference symbol 7a. These protruding parts are usually intact. fresh

Department of Economics and Intellectual Property Bureau of the Intellectual Property Bureau, printed clothing for consumer cooperatives 20 200414417 A7 B7 V. Description of the invention (13) and located around the surface of the donor wafer 10, then, all the protruding parts are commercially known as "" Remove the ring. " Therefore, for example, known removal techniques, such as those that we will study further and later in this document (such as the Smart-5 cut © technology already mentioned), sometimes result in, for example, removal of the surface The surface roughness is indicated by the reference symbol 7b. Once the removal is performed, the recovery according to the present invention is operated to restore the donor wafer 10. Generally speaking, recycling includes two steps: 10 • removing material; • reducing at least a portion of the donor wafer 10. The first step of recycling according to the present invention is to remove at least the uneven portions 7a and 7b (shown in Fig. 2). The removal of such a substance according to the present invention is such that after the removal, at least a portion of the buffer structure I remains, which can be reused during the subsequent removal of the new useful layer. After the substance is removed, the remaining portion of the buffer structure I is thus recovered, unlike the known recovery of conventional techniques. In the first special case of recycling in the case of the first special case of recycling by the Intellectual Property Bureau of the Ministry of Economic Affairs, and regarding the second mode of removal 20 (2), it is advantageous to choose the thickness of the upper cover so that after removal, the upper cover The remaining part of the layer (for the removed layer 7) is removed by standard mechanical means (such as polishing or CMP) to remove the substance, without removing the substance from the safe buffer structure I, thereby retaining the entire buffer Construct I. Even if the current development can smoothly reach a thickness of about 1 // m, recycling -15- This paper size is applicable to China National Standard (CNS) A4 (210 x 297 mm) 200414417 A7 B7 The fifth, invention description (14) The thickness of the material removed by standard mechanical means (such as polishing) is generally about 2 // m. In the second special case of recycling, and regarding the second mode (2) of the removal, it is more advantageous to select the thickness of the upper cover layer and the additional layer 4 so that 5 after the removal, the remaining portion of the upper cover layer (for At least a part of the removed layer 7) and the additional layer 4 are removed by standard mechanical means (such as polishing means or CMP) for removing the substance without removing the substance from the secure buffer layer 2, thereby Keep the entire buffer layer 2. With regard to another special case of recycling, removal of the substance is preferably the use of a means that chemically erodes the material (e.g. chemical etching). Etching may be pure chemical, electrochemical, photoelectrochemical, or any other equivalent etching, such as the one used during chemical mechanical polishing. In one advantageous etching mode, selective etching is achieved. Therefore, it is particularly possible to use an etching fluid (ie, a gas or a solution) suitable for performing selective etching of 15 materials that are removed from the material to be recycled, two materials, which belong to adjacent layers and enable the material to be recycled A #etch stop layer is formed to effectively remove the part to be removed, while protecting the layer to be recovered from chemical etching. The selectivity characteristic between two materials can be obtained, for example, in at least one of the following cases:-the two materials are different; or-the two materials contain atomic elements that are substantially the same except for at least one atomic element; or-both The materials are essentially the same, but at least one of the original materials is -16- This paper size applies to China National Standard (CNS) A4 (210x297 mm)

200414417 A7 B7 V. Description of the Invention (I5) The child element has an atomic concentration of a substantially different atomic concentration > from another material; or-the two materials have different porosity densities. For example, when containing, for example, KOH (potassium hydroxide, selectivity of about 1: 100 5), NH4OH (ammonium hydroxide, selectivity of about 1: 100), or TMAH (tetramethylammonium hydroxide) When the solution of the compound is engraved with Si, I know that SiGe acts like a stop layer. For example, I know that when SiGe has a germanium concentration of 25% or more, it acts as a stop when etching 10 SiGe (with a germanium concentration of 20% or less) in a solution containing a compound such as TMAH. Floor. For example, I know that if Si is properly doped with a doping element at a selected concentration (for example, boron of 2 X 1019 cnT3 or more), it should contain, for example, EDP (ethylenediamine catechol), KOH, or N2H2 ( The solution of the compound of hydrazine) is used as a stop layer when etching an undoped Si material. For example, I know that porous Si is etched by selective etching using a solution containing a compound such as KOH or HF + H202, as opposed to non-porous crystalline Si. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. Therefore, it is possible to selectively etch additional layers 4 and / 20 relative to the buffer layer 2 or possible upper covering layers relative to the additional layer 4 or possible interlayers. This removal of the substance by chemical means may also be accompanied by the use of mechanical or other means to attack the substance. In particular, it is possible to perform CMP polishing with a selective chemical etching solution. This kind of chemical etching can also be performed by using corrosive substances (such as polishing, grinding, -17- this paper size applies Chinese National Standard (CNS) A4 specifications (210x297 mm) 200414417 A7 B7 V. Description of the invention (16) Erosion) Removal of the substance by mechanical means or by any other means • before or after. In general, the removal of a substance may include any other means of using a substance that is invasive, capable of removing the substance without completely removing and damaging at least a portion of the buffer structure I-5. Therefore, one of the following substance removal modes is used: (a) removing a part of the layer 7 after removal which contains at least the uneven portions 7a and 7b; or (b) removing the entire layer 7 after removal; or 10 (c ) Remove a part of the layer 7 and the buffer layer 2 after the removal. If the removed layer 7 includes a part of the original upper cover layer, the material removal mode (a) preferably includes the portion of this upper cover layer that is completely removed. Referring to FIG. 3, a residual portion of the original buffer structure after the material is removed is denoted by reference symbol Γ. It includes: Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs • The entire original buffer structure I, when using the material removal mode (a) and when the material removal mode (a) does not involve the removal of any part of the additional layer 4 ; Or-a part of the buffer layer 2 and the additional layer 4 when using the substance removal mode 20 (a) and when the material removal mode (a) involves removing a part of the additional layer 4; or-the buffer layer 2 when used When the substance removal mode (b); or-part of the buffer layer 2, when the substance removal mode (c) is used. After the first recovery step on substance removal, the second recovery step package-18- This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 V. Description of the invention (17) including reformation At least some layers removed during the first step. • First of all, in some cases, it is better to trim the surface of the donor wafer 10. The material removal that operates during the first recovery step occurs on the surface of the donor wafer 10, and cannot be removed during the material removal. Any 5 roughnesses that may have manifested. To this end, for example, CMP polishing, heat treatment or another leveling technique will be used so that the misalignment and other defects confined in the buffer structure I will not grow, will not increase in size and will not create any sliding surfaces, stacking defects or Other defects can reduce the quality of the cushion structure I. 10 When a part of the original buffer structure I is removed during the first recovery step, this second recovery step involves restoring the buffer structure I from the remaining buffer structure Γ. Once the reduction of the buffer structure I is formed, it is preferable to make it substantially the same as the original buffer structure I. 15 However, in a particular embodiment, it will be possible to change some production parameters slightly in order to obtain a cushioning structure I slightly different from the original. For example, the concentration of certain compounds in the material will be slightly changed. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. Reducing the buffer structure I involves re-forming the removed portion of the buffer layer 2 when a portion of the original buffer layer 2 is cut off during the first recovery step. 20 The reduction buffer structure I involves reforming all or part of the additional layer 4 when all or part of the original additional layer 4 is cut off during the first recovery step. In this case, it would be possible to produce an additional layer 4 having a thickness that is substantially the same as or substantially different from the original. -19- This paper size is in accordance with Chinese National Standard (CNS) A4 (210x297 mm) 200414417 A7 B7 V. Description of the invention (18) Once the buffer structure I is restored, the upper cover layer may be formed on it. Among them, The upper cover layer will at least partially contain the new useful layer to be removed, and one or more interlayers that may be included between the buffer structure I and the upper cover layer. 5 The layers that may form during this second recovery step are preferably created on their respective underlying layers by layer growth (such as by CVD or MBE epitaxial growth). In the first case, at least one of these layers is in situ and directly continues to form the growth support of the lower layer. In this case, the growth support of the lower layer is also preferably formed by layer growth. In the second case, at least one of these layers is grown after a minor step of trimming the surface of the underlying growth support (such as by CMP polishing, heat treatment, or other planarization techniques) to limit the misalignment in the buffer structure I It does not grow with other defects, does not increase size, does not create any sliding surfaces, stack 15 defects, or other defects that degrade the quality of cushioning structure I. Therefore, in addition to the modifications expected and realized by those skilled in the art, a donor wafer 10 that is substantially the same as the original is obtained, that is, the donor wafer 10 shown in FIG. 1. The donor property cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs printed the donor wafer 10 obtained in this way, which contains at least a part of the original buffer structure I, and therefore contains at least a part of the original buffer layer 2. This avoids the situation as known recycling methods All of them, long and expensive reformations are possible. The donor wafers 10 that can be recovered according to the specific operation mode of the above-mentioned recovery method are described in the rest of this document. They are referred to during the matching recovery period. 200414417 A7 B7 V. Description of the invention (for particularly effective protection to at least a part of the buffer structure I. • The donor wafers 10 shown in FIGS. 4, 5 and 6 each have a substrate 1 and a buffer structure I, Like the donor wafer 10 shown in Fig. 1. Each donor wafer 10 further includes a protective layer 3 on the side of the buffer structure I which is the same as the buffer structure I and the 5 interface of the substrate 1. The definition according to the present invention The protective layer 3 is composed of a material selected from a crystalline material (such as a semiconductor), and can not only have the main function of protecting the portion of the donor wafer 10 below it, but also remove at least one substance used during recovery During this period, it contains at least part of the buffer structure I. 10 The protective layer 3 is preferably generated on the lower growth branch by layer growth (eg, by CVD or MBE epitaxial growth). In this configuration, and in the first case, the growth of the protective layer 3 is in place, and it is directly achieved by the formation of the underlying layer. In this case, the underlying layer is also preferably formed by layer growth. 15 In the second case, the growth of protective layer 3 is printed by the consumer co-operatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, trimming the layers below it. The surface is a secondary step (such as by CMP polishing, heat treatment, or other leveling techniques). It is then implemented so that the misalignment and other defects confined in the buffer structure I do not grow, do not increase in size, and do not create any sliding surfaces, stacking defects, or other defects that reduce the quality of the buffer structure I. 20 The material of the protective layer 3 is selected so that there is at least one means for removing a substance having the ability to erode the material forming the protective layer 3, which is substantially the material of at least one of the two zones adjacent to the protective layer 3. Different. Therefore, it is possible to operate a selective substance removal. The selective substance removal operating in the protective layer 3 is at least one of the following options-21- This paper size applies to Chinese national standards ( CNS) A4 specification (210 X 297 mm) 200414417 A7 B7 V. Description of the invention (2) Selective substance removal mode: *-Relative to protective layer 3, it is useful to be adjacent to protective layer 3 and to be removed. Selective removal of material in the zone on the side of the layer, the protective layer 3 forms a stop layer for material removal; 5-selective removal of the material of the protective layer 3, which forms a stop on the protective layer 3 When removing one layer of the blocking substance, it is performed in a zone adjacent to the protective layer 3 and located on the side of the substrate 1. In a special operation of selective substance removal, it is also possible to combine two selectivities for the same protective layer 3. The continuous operation of the substance removal mode. 10 Therefore, the layer above the protective layer 3 and then the protective layer 3 is selectively removed. Regardless of the selective substance removal mode of that portion of the donor wafer 10 that is selected for operation during the first recovery step and is intended to be removed on the side of the removed useful layer, there is a stop substance movement Divided by one layer 15 (the protective layer 3 in the case of the first selective substance removal, or the zone adjacent to the protective layer 3 in the case of the second selective substance removal, the protective layer 3 is located in Substrate 1 on the same side). Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Therefore, the stop layer acts as an obstacle to the erosion of the material, and similarly, it protects the material located under the protective layer 3 (which contains at least a 20 part of the buffer structure I). In some cases, we will hope that the protective layer 3 will not substantially disturb the crystal structure of the adjacent layer, and especially that it will not disturb the crystal growth of the underlying layer to be formed. In most cases, its lattice parameters must be substantial The upper obeys the lattice parameters of the part below the protective layer 3. -22- This paper size applies to China National Standard (CNS) A4 (210 x 297 mm) 200414417

Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs It is particularly important when the protective layer 3 is located at the buffer hibiscus and skin. In Huahua 1 (shown in Figure 4) 'The last result is based on the number of Bao 3 ... bite the first vertical as shown below in protective layer 3 # y 丨 丄 柊 夂 教 杏 所In the example, even if the nominal crystal lattice number of these two materials is different, the number of lattices of the θ J cake is different from that of the protective layer, and the number of lattices of θ J is different. The lattice parameters of the zone immediately following it are essentially the same. In order for this operation to be successful, two main conditions must be met: The / shroud layer * 3 and the nominal parameters of the zone below it do not have values that are too different from each other, and defects (such as misplacement or Local strain) occurs in the protective layer 3; The protective layer 3 must be thin enough to avoid the gradual release of strain and / or defects in the thickness of the layer. For this reason, the thickness of the protective semiconductor layer 3 made of strained crystalline material must be smaller than the thickness of the L-boundary, which is familiar to those skilled in the art, and especially depends on the material forming it and the material of the layer adjacent to it. And techniques to produce strained layers. As a result, critical thicknesses typically encountered are less than or equal to several hundred Angstroms. '' Some examples of standard critical thickness " can be found in Friedrich Schaffler, High-Mobility Si and Ge Siructures, 20 "(" Semiconductor Science and Technology "12 (1997) 1515-1549) Found. In the second embodiment of the protective layer 3, it is 5 10 Γ 15 -23-which has a nominal crystal lattice parameter (substantially close to the nominal lattice parameter of the material forming the zone adjacent to it). Applicable to China National Standard (CNS) A4 specification (210 X297 mm) 200414417 Α7

The protective layer 3 is selected from a material. • 造 是 =: like the first embodiment of the protective layer in this case

Substance 2: Purpose 'is also in order to meet the standard of the material: f sex during the first recovery step, such as to maintain the same, while the two elementary system and the constituent elements adjacent to it from time to time, quasi-hold The lattice parameter is close to the lattice parameter of the adjacent zone. This constituent element is therefore the main element that will determine the selectivity relative to the adjacent layer in question. 10 15 Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs, Employee Consumer Cooperatives. 20 In a special case In the following, the constituent element materials of the material of the protective layer 3 are not found to be completely different among the materials constituting the selective zone. U the two In another special case, each of Baoxian 3 may not be relative to the neighbouring areas involved in the selective removal of matter, and may be an extra element or an element missing from the adjacent layer in question. For example, it will be possible to dope the layer 3 with a lattice parameter substantially the same as the lattice number of the adjacent zone, so as not to substantially disturb the lattice parameter after the doping. ^ If the protective layer 3 is composed of the same material as the material adjacent to it and involves the removal of a selective substance, such a doping element is an element with a selective selectivity. Μ However, in the case of doping the protective layer 3, if we expect that, for example, misplaced, especially spiral-type defects will not occur, the thickness of the protective layer 3 in some cases' must be maintained smaller than that of those skilled in the art Well-known — -24— This paper size applies to Chinese National Standard (CNS) A4 # βΤΙΪ ^ χ297mm 200414417 A7 B7 5. Description of invention (23) Specific critical thickness. • In the third embodiment of the protective layer 3, the surface of the layer produced in advance is made porous to form a porous layer. Such porosification may be achieved by anodization, by implantation of protosubstances, or by any other porosification technique, as described in document EP 0 849 788 A2. Such a layer of porous material may produce a protective layer 3 when at least one adjacent material may be subjected to a selective substance attack determined by appropriate etching means. Such a protective layer 3 is preferably between two and ten adjacent layers having substantially the same respective materials, in other words, between a layer whose surface has been made porous and a layer formed on the porous material layer. Since the porosity does not substantially disturb the crystalline structure of the two adjacent layers, the protective layer 3 therefore does not substantially disturb the crystalline structure of the donor wafer 10. 15 Therefore, the protective layer 3 is obtained with a crystal structure that is very close to or even substantially the same as the crystal structure of the zone adjacent to it. Therefore, the protective layer 3 does not disturb the crystal structure of the surrounding structure. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. However, in other cases, there may be a protective layer 3 that has some influence on the lattice parameters of the surrounding structure. In these special cases, the protective layer 3 can lead to proximity. All layers or relative strain or relaxation states of the layers exhibit characteristics that are considered to be of minimal benefit to downstream applications. Several selective substance removal techniques may operate on the protective layer 3. The first selective substance removal technique consists in applying friction to the protective layer 3 in order to remove at least a part of the substance to be removed. -25- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (24) These frictional forces can be applied, for example, by a polishing plate, and may have an abrasive effect • and / Or a combination of chemistry. The material for forming the protective layer 3 is selected from crystalline materials, so there is a method of mechanical substance erosion, which has mechanical erosion ability. The mechanical erosion ability 5 is at least for the material forming the protective layer 3 and the two zones adjacent to the protective layer 3. The materials of a zone are substantially different, so the mechanical material invasion method can operate at least one selective mechanical erosion method. Therefore, the selective mechanical erosion method is one of the following mechanical erosion methods: 10-the selectivity of the material in the zone adjacent to the protective layer 3 and on the side of the useful layer that has been removed relative to the protective layer 3 Mechanical erosion. The material of the protective layer 3 therefore has the characteristics of withstanding mechanical erosion, and these characteristics are substantially larger than those of the area above it. For this purpose, for example, it is possible to harden the protective layer 3 with respect to the upper cover layer by means of a mechanical erosion method suitable to choose to remove the upper 15 cover area. So, for example, we know that Si carbonate with a typical C concentration between 5% and 50% is harder than non-carbonate Si. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-selective mechanical erosion of the material of the protective layer 3, which is adjacent to the protective layer 3 and is located on the same side of the substrate 1 as the protective layer 3 forming the 20 etch stop layer The Strip takes place. The material of the protective layer 3 has characteristics of withstanding mechanical erosion, especially corrosion, and these characteristics are substantially smaller than those of the zone located above it. For example, it may be possible to use a substance suitable for removing the protective layer 3-26. This paper size applies the Chinese National Standard (CNS) A4 specification (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (25) Removal technology In this way, the protective layer 3 is softened relative to the underlying layer. • The second selective substance removal technique consists in chemically etching the substance to be removed. Wet etching may be performed with an etching solution suitable for the material to be removed. Dry etching such as plasma etching or sputtering can also be performed to remove the substance. Furthermore, the etching may be purely chemical, electrochemical, or photoelectrochemical. The material for forming the protective layer 3 is selected from the crystalline material, so there is an ability to form the protective layer 3 with the last name, and then an etching fluid (gas or solution) capable of performing at least one selective etching method to form a protective layer The material of 3 is substantially different from the material of at least one of the two zones adjacent to the protective layer 3. The selective etching method is one of the following etching methods: 15-Selective etching of the material of the zone on the side of the useful layer adjacent to the protective layer 3 and located on the side of the protective layer 3 which has been removed. Layer 3 forms a stopper layer; the selective etching of the protective layer 3 material printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs is adjacent to the protective layer 3 relative to the protective layer 3 forming the etch stop layer The strips are located on the same side 20 of the substrate 1. Regardless of the selective etching method that may function during recovery and is intended to remove that portion of the donor wafer 10 on the same side of the removed useful layer, there is a stop layer (the first #etching method) In the case of this protective layer 3, or in the case of the second selective etching method, it is adjacent to -27- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 200414417 A7

26 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, protective layer 3, which is located on the same side as the substrate i). Therefore, the stopper layer serves as a barrier to the chemical plutonium, and similarly protects the material (which includes one element of the buffer structure j) located under the protective layer 3. As already explained above, the selectivity to remove substances between the material of the protective layer 3 and the material of the adjacent zone involving the selective side may be obtained by the fact that: b-the two materials are different Or-the two materials contain substantially the same atomic element, except for at least one of the original 10 child elements; or ',-the two materials are substantially the same, but at least one atom in one material Atomic concentrations different from those of the same atomic element in another material; or-the two materials have different porosity densities. Referring to FIG. 4, the protective layer 3 is within the buffer structure j, and the donor wafer 忉 thus includes a structure composed of the following four continuous layers: the support substrate i, the lower portion 2 of the buffer structure I, the protective layer 3, and the buffer Structure I upper part 4 ,. Here 'the protective layer 3 makes it possible to protect the lower portion 2 of the buffer structure I. The recovery of such a donor wafer 10 according to the present invention, during the first step, consists in removing all the parts on the side of the upper part 4 located on the same buffer structure as the protective layer 3. In the protective layer 3, the selective substance removal mode is at least one of the following selective substance removal modes:-removing material from the zone 4 adjacent to the protective layer 3, the protective layer 5 15 20 -28-

200414417 A7 B7 V. Description of the invention (27) 3 forms a layer of removal of the stopper; •-material is removed from the protective layer 3, and the area adjacent to the portion 2 'of the protection layer 3 forms a layer of removal of the stopper . Regardless of the mode of selective substance removal that may operate during recovery and is intended to remove part 4 'of the adjacent protective layer 3 5, there is a layer of removal of the stop substance (in the first selective substance removal In the case of the mode, it is the protective layer 3, or in the case of the second selective substance removal mode, it is adjacent to the part 2 'of the protective layer 3.) This layer is further used as a barrier to material erosion or etching. The material of the lower portion 2f of the ground protection buffer structure I. 10 Therefore, the crystalline structure of buffer structure I is not substantially disturbed. This type of protective layer 3 must have its own crystalline structure (substantially the same as the crystalline structure of the zone adjacent to buffer structure I), so it must be based on One embodiment (such as one of the three embodiments already discussed) that makes it possible to obtain this material property can be produced. 15 After removing the material above 2 'below the buffer structure I, it is printed back to the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. The harvest is preferably generated by the new upper 4' containing buffer structure I, and may include The creation of a new protective layer 3 where the protective layer 3 has been removed (during the above-mentioned second selective substance removal mode or by a process suitable for removing this layer 3). 20 These layers 3 and 4 'may be grown in situ or after trimming the surface of the donor wafer 10 on which growth will occur (for example, by CMP polishing, heat treatment, or other planarization techniques) to confine the structure to a buffer The misalignment and other defects in I will not grow, will not increase in size, and will not create any sliding surfaces, stacking defects, or other defects that will reduce the quality of the cushioning structure I. -29- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (28) The lower part 2 'of the buffer structure I was therefore retained during the recovery period, and the know-how This is not the case. In the special and advantageous configuration of the donor wafer 10, the lower part 2 'of the buffer structure I is a buffer layer, and the upper part 4' of the buffer structure I is an additional layer added to the buffer layer 5, as shown in the figure. The buffer layer 2 and the additional layer 4 shown in FIG. 1 and discussed above. This special configuration has the advantage of protecting the buffer layer 2 '(in other words, the part of the buffer structure I that is generally the most difficult, longest and most expensive to produce). 10 Because the additional layer 4 ′ is usually formed by epitaxial growth combined with fixed parameters (such as the concentration, temperature, pressure, atmospheric pressure, growth rate, and rate of the element to be epitaxially grown), and the layer is removed from the donor wafer 10 During this step itself is the subject of removal, so it does not seem necessary to protect this additional layer 4 'by the protective layer 3 during recovery. 15 However, in another special configuration of the donor wafer 10, the protective layer 3. may be positioned within the additional layer 4 'in order to protect at least a portion thereof. In yet another special configuration, the protective layer 3 is formed inside the buffer layer 2 'so as to protect only a part thereof, such as the part which is most difficult to generate. Printed with reference to FIG. 5 by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. The second donor wafer 10 according to the present invention is different from the donor wafer 10 shown in FIG. 20 in that the protective layer 3 is no longer located in the buffer structure I. Instead, it is directly above the buffer structure I. Furthermore, the upper cover layer 5 is present on the protective layer 3, wherein at least a part of the useful layer will be removed from the donor wafer 10 when one layer is transferred. The composition and crystalline structure of the upper cover layer 5 will be based on physical and electrical -30- This paper size applies the Chinese National Standard (CNS) A4 specification (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (29) Properties and / Or mechanical properties, it is expected that a post-transfer structure can be obtained. • The material of this overlying layer 5 may, for example, have a nominal lattice parameter that is substantially the same as the nominal lattice parameter of the buffer structure I in the portion adjacent to the protective layer 3, so that it cannot maintain a substantially relaxed structure. 5 The material of the upper cover layer 5 may also have, for example, a nominal lattice parameter that is substantially different from the nominal lattice parameter of the buffer structure I in a portion adjacent to the protective layer 3, and has a sufficiently small thickness, so its It is necessary to maintain the lattice parameter of the buffer structure I in the part adjacent to the protective layer 3, and then to be strained. For example, the material of the upper cover layer 5 may be selected again to have a centered structure between the strained structure and the relaxed structure. In an advantageous configuration, the upper cladding layer 5 is produced by layer growth (for example by CVD or MBE epitaxial growth). In this configuration, and in the first case, the growth of the upper cladding layer 5 is in place, and the formation of the upper part of the buffer structure I is directly continued to be realized. In this case, the buffer structure I is also preferably Formed by layer growth. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. In the second case, the growth of the upper cover layer 5 is a secondary step in trimming the surface of the upper surface of the lower buffer structure I (such as by CMP polishing, heat treatment or other leveling technology ), So that the misalignment and other defects confined in the buffer structure I will not grow, increase the size and create no 20 sliding surfaces, stacking defects or other defects that will reduce the quality of the buffer structure I. Regarding the protective layer 3, its role in this case is to substantially protect all of the lower buffer structure I and the substrate 1 from the removal of substances that are operated during the first recovery step. The useful layer has been removed from the donor wafer 10 above the cover layer 5 -31- This paper size applies to the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 Printed by the employee's consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs V. Description of the invention After (30), the recovery of such donor wafer 10 during the first step consists in substantially removing all the parts located on the side of the cover layer 5 which is the same as the protective layer 3. In the protective layer 3, the selective material removal mode is at least one of the following selective material removal modes:-removing the material adjacent to the cover layer 5 above the protective layer 3, which forms a stop material removal One layer;-the material of the protective layer 3 is removed, and the area adjacent to the buffer structure I of the protective layer 3 forms a layer of removal of the stopper substance. 10 Regardless of the selective substance removal mode that may be operating during recovery and intends to remove the remaining upper cover layer 5, there is a layer that has a stop substance removal (in the first selective substance removal mode) In this case, the protective layer 3, or in the case of the second selective substance removal mode, the area adjacent to the upper part of the buffer structure I of the protective layer 3), this layer is further used as a barrier to material etching 15 or erosion, The material of the cushion structure I is protected in the same way. Furthermore, it may be advantageous that the protective layer 3 does not substantially disturb the crystal structure of the buffer structure I located directly below, and does not disturb the crystal growth covering the upper cover layer 5 in order to maintain the structural pair of the buffer structure I. The effect of the structure of the growing overlying cover 5 is therefore preferably based on one of the three embodiments already discussed. After the removal of the material covering the buffer structure I, the recycling preferably includes the creation of a new upper cover layer 5, and perhaps the generation of a new protective layer 3 (in the case where the protective layer 3 has been removed) During the above-mentioned second selective substance removal mode or by a process suitable for removing this layer 3). -32- This paper size applies to China National Standard (CNS) A4 (210 x 297 mm)

200414417 A7 B7 V. Description of the invention (30 These layers 5 and 3 may be minor steps in situ or on the surface of the growth wafer 10 (such as by CMP polishing, heat treatment or other planarization) Technology), so that the misalignment and other defects confined in the buffer structure I will not grow, increase the size and create no sliding surface, stacking defects or other defects that will reduce the quality of the buffer structure I. Referring to Fig. 6, the fact that the third donor wafer 10 according to the present invention is different from the donor wafer 10 shown in Fig. 3 is that there is an interlayer 8 between the buffer structure I and the protective layer 3. The composition of this interlayer 8 The crystalline structure will be selected as a function of the desired physical, electrical, and / or mechanical properties. The material of the interlayer 8 may, for example, have a nominal crystal that is substantially at the interface adjacent to its interface with the buffer structure I The nominal lattice parameters with the same lattice parameters can not maintain a substantially relaxed structure. In this case, the interlayer 8 is an extension of the buffer structure I, which may, for example, further strengthen the growth of the upper cover layer 5 Table 15 shows the crystalline rigidity. The material printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs of this interlayer 8 may also have, for example, a nominal lattice parameter that is substantially different from the nominal lattice parameter of the portion of the buffer structure I adjacent to its interface. Lattice parameters and have a lattice parameter that is low enough to maintain the buffer structure I in its portion adjacent to the protective layer 3, and thus subject to strain thickness. 20 In an advantageous configuration, the interlayer 8 or the overlying cover layer 5 is generated by layer growth (such as by CVD or MBE epitaxy). In this configuration, and in the first case, the growth of the layer in question is in place and directly continues to the formation of the underlying layer, In this case, the lower layer is also best formed by layer growth. -33- This paper size applies the Chinese National Standard (CNS) A4 specification (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (32) In the second case, the growth of the layer in question is achieved after a minor step of trimming the surface of the upper surface of the lower layer (such as by CMP polishing, heat treatment or other planarization techniques), so as to limit the The placement and other defects will not grow, will not increase in size and will not create any sliding surface, stack 5 defects or other defects that will reduce the quality of the cushion structure I. Regarding the protective layer 3, its role in this case is to In fact, the entire lower interlayer 8, the entire buffer structure I, and the substrate 1 are protected from material removal during the first recovery step. In the protective layer 3, the selective material removal mode is at least one of the following options 10 Sexual substance removal mode:-remove the material adjacent to the cover layer 5 above the protective layer 3, which forms a layer of stop material removal;-remove the material of the protective layer 3, between adjacent protective layers 3 The zone of layer 8 forms a layer of removal of the stopper material. 15 It may operate during the recovery period and is intended to remove the remaining overlying selective material removal of the cover layer 5 printed by the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economy Whatever the mode, there is a layer that removes the blocking substance (the protective layer 3 in the case of the first selective substance removal mode, or the adjacent protective layer in the case of the second selective substance removal mode). The zone between layer 3 and layer 8), which in turn serves as a barrier to material etching or erosion, and similarly protects the material of buffer structure I. Furthermore, it may be advantageous that the protective layer 3 does not substantially disturb the crystal structure of the interlayer 8 located directly below, and does not disturb the crystal growth covering the upper cover layer 5 in order to maintain the structure of the interlayer 8 The impact of the structure of the covering layer 5 above the growth, so it must be based on the two realities that have been discussed. This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 Employees of the Intellectual Property Bureau of the Ministry of Economic Affairs Produced by the Consumer Cooperatives 5. Invention Description (33) One of the examples. After the removal of the substance on the interlayer 8, the recycling preferably includes the creation of a new upper cover layer 5, and perhaps in the condition that the protective layer 3 has been removed (in the second selective substance removal described above) During the mode or by a process suitable for removing this layer 3 5) involves the creation of a new protective layer 3. These layers 5 and 3 may be grown in situ or after trimming the surface of the donor wafer 10 on which growth will occur (for example, by CMP polishing, heat treatment, or other planarization techniques), which is performed to limit the The misalignment and other defects in the cushioning structure I will not grow, will not increase in size, and will not build any sliding surfaces, stacking defects or other defects that will reduce the quality of the cushioning structure I. 7a to 7f, which show various steps of a method of removing a thin layer from a donor wafer 10 and recovering the donor wafer 10 including a protective layer 3, which uses layers having substantially the same layers as described in FIG. 4 above. The donor wafer 10 having the same 15-layer structure is structured. Therefore, referring to FIG. 7 a, it includes a substrate 1 and a buffer structure 1 with a protective layer 3 inside. In the example we will study, the protective layer 3 removes one buffer layer 2 and one additional layer 4 in the buffer structure I. In this exemplary method according to the present invention, an additional cover layer 5 has been added on top of the additional layer 4. The removal to be achieved during this method will be associated with the removal of part of the additional layer 4 and the upper cover layer 5. Similarly, in other structural configurations of the donor wafer 10, 'there may be several upper cover layers, and the removal will then be with the upper cover layer, and maybe with additional layers. 210 x297 mm)

200414417 A7 B7 V. A part of the description of the invention (34) is related, or there may be no upper cover layer, and the removal will only be related to a part of the additional layer 4. Furthermore, it is often necessary to have a relatively thin protective layer 3: as already explained above, a too thick protective layer 3 will affect the crystal characteristics of the buffer structure I, for example, producing defects such as misalignment, or lattice parameters. change. For this reason, the thickness of the protective layer 3 must be smaller than the critical thickness. In this case, exceeding the critical thickness will obtain an undesired effect. The four layers 2, 3, 4 and 5 are preferably formed by stupid crystal growth (such as by CVD and MBE) according to known techniques. 10 In the first case, at least one of the four layers is In the original place, the growth of the lower-floor growth branch is directly continued to grow. In this case, the lower-floor growth branch is also preferably formed by growing the floor. In the second case, at least one of these four layers is grown after a minor step of trimming the surface of the underlying growth support (such as by CMP polishing, heat treatment or other 15 leveling techniques), which is performed to limit the Misplacement and other defects in the cushioning structure I will not grow, will not increase in size, and will not create any sliding surfaces, stacking defects, or other defects that will reduce the quality of the cushioning structure I. A method for removing the thin layer is shown in Figures 7b and 7c. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs The first preferred removal step of the present invention is to establish the fragile 20 zone in the additional layer 4 in order to perform the subsequent separation to separate the desired layer. Here are some techniques that can be operated to establish this kind of fragile zone: The first technology is known as Smart-cut® technology (and its description may be covered in some It is found in the literature of technology), which is in the first step of implanting atoms with a specific energy -36- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 200414417 A7- ---- B7 V. Invention Description 35 Substances (such as hydrogen ions) 'in order to establish fragile zones in this way. The second technique consists in forming a surface by creating at least one porous layer, as described in document EP-A-0 849 788, for example. In this exemplary method according to the present invention, the fragile zone formed according to one of the two technologies is preferably established on the upper side to cover the eyebrows, ^ ύ and Fulikou layer 4 or on the additional layer 4 in. When the upper cover layer 5 is thick enough, a fragile zone may be formed in JK,, / ,. In particular, this is the case where the upper cover layer 5 is composed of a stack. 10 15 Printed by the Consumer Property Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 20 Referring to Fig. 7b, the second step for removing a thin layer consists in attaching the cover 6 to the surface of the upper cover 5. The soil receiving substrate 6 forms a mechanical support. The rigidity of the mechanical support is large enough to support the cover layer 5 removed from the donor wafer 10, and it is sufficient to protect the ancient mantle from any mechanical strain from the outside. Such a receiving substrate 6 may be made of, for example, crushed or quartz or another type of material. '' The receiving substrate 6 is placed in close contact with the upper cover layer 5 and bonded to it for attachment. The molecular adhesive is preferably between the substrate 6 and the upper cover layer 5. Apply. This bonding technology together with the modification is specifically described in the title of q γ Tung, U. Gosele, and Wiley, which is semiconductor wafer bonding (Science and technology, interscience

Technology). If necessary, the joining is accompanied by appropriate pre-treatment of the individual surfaces to be joined and / or with the supply of thermal energy and / or the provision of additional adhesives. • 37- This paper size applies Chinese National Standard (CNS) A4 (210x297 mm) 200414417 A7 B7 V. Description of Invention (36) Therefore, for example, the heat treatment applied during or just after bonding may cause The joint connection is hardened. The bonding can also be controlled by a bonding layer such as Silica, which is interposed between the upper cover layer 5 and the receiving substrate 6 and has a polymer bonding ability, in particular. It is advantageous that the material forming the joint surface of the receiving substrate 6 and / or the material that can form the joint layer is electrically insulated in order to generate the SOI structure from the removed layer. Then, the semiconductor layer of the SOI structure is The cover layer 5 is covered 10 together with a part of the additional layer 4 or transferred without a part of the additional layer 4. Once the receiving substrate 6 is bonded, a part of the donor wafer 10 is removed from the previously formed fragile zone by separating it. In the case of this first technology (Smart-cut®), in the second step, the implantation zone (forming the fragile zone) is subjected to heat and / or mechanical treatment, or other energy supply, to facilitate the fragile zone Make it separate. In the case of this second technique, the fragile layer is provided with mechanical processing or other energy to facilitate its separation. The Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs prints that the separation of the fragile area based on one of these two technologies makes it possible to remove most of the wafer 10 in order to obtain the rest of the upper part, which may include the buffer structure I 20 The structure of layer 5, any bonding layer and receiving substrate 6. Then, it is preferable to operate the step of removing the surface of the structure formed by the removal layer, so as to remove any surface roughness, uneven thickness, and / or thickness by using, for example, chemical mechanical polishing CMP, etching, or at least one heat treatment. -38- This paper size applies to China National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 V. Description of the invention (37) The desired layer. After the removal of the layer 7, a portion remaining on the protective layer 3 is formed, and the entire wafer is formed into a donor wafer 10f to be transferred for recycling, so that it can be reused later during the removal of another layer. 5 The recovery steps are shown in Figures 7d, 7e and 7f. Referring to Fig. 7d, the first recovery step is equivalent to actually removing all the layer 7 after removal, and it is possible to remove the protective layer 3. Mechanical or chemical-mechanical erosion or appropriate treatment may and may be operated first, in order to remove the rest of the additional layer 4 of the removed layer 7 by, for example, grinding, polishing, CMP, chemical etching, heat treatment, and 10 leveling techniques. In part, it is implemented so that the misalignment and other defects confined in the buffer structure I do not grow, do not increase in size, and do not create any sliding surfaces, stacking defects, or other defects that reduce the quality of the buffer structure I . Several of these material etching or etching techniques may also be combined or succeeded, such as by chemical etching and continuous invasion by CMP. In all cases, the first recovery step includes the use of at least one of the selective substance removal modes discussed above. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs with reference to Figures 7e and 7f. The second recovery step is equivalent to forming an additional layer 2 'with an additional layer 4' and an upper cover layer 5 ', respectively, to restore substantially the same as existing before removal. Those layers are the same. Furthermore, the reduction includes the formation of the protective layer 3 that has been removed. These layers are preferably reduced by forming a layer according to a technique (substantially the same as one of these techniques). -39- This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210 X 297 mm) 200414417 A7 B7 V. Description of the invention (30 donor wafer 10 " 'Layer 4' and 5 'obtained do not need to be connected with Layer 4 of donor wafer 10 is the same as 5, and the donor wafer shown in FIG. 7d may be used as a substrate for other types of layers. In the exemplary method according to the present invention that has just been described in detail, the removal is about 5 additional layers 4 and Part of the upper cover layer 5. At the same time, this example can be applied to remove only a part of the additional layer 4 (the donor wafer 10 does not have the upper cover layer 5). At the same time, this example can be applied to remove only the upper cover layer 5 One part, then, recycling includes removing the remaining part of the upper cover layer 5. 10 In the exemplary method according to the invention which has just been described in detail, the protective layer 3 is located between the buffer layer 2 and the additional layer 4. Obviously, This example is also suitable when the protective layer 3 is located in the buffer layer 2 or in the additional layer 4. In general, this example extends to the case where the protective layer 3 is located in the buffer structure I 15. Refer to FIGS. 7a to 7f With the explanation of the method according to the present invention using the donor wafer 10 shown in FIG. 2, it can also be easily replaced with the donor wafer 10 shown in the following figure: Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -Figure 5 by placing the protective layer 3 between the buffer structure I and the upper cover layer 20 5 instead of placing it in the buffer structure I, this layer is then removed from the upper cover layer 5 for recycling The removal of the substance ends with the selective etching of the upper cover layer 5 relative to the protective layer 3 and / or the selective etching of the protective layer 3 relative to the buffer structure I. Fig. 6 by adding the interlayer 8 to the donor wafer 10 And set it to -40- This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 V. Description of the invention (39) Between the buffer structure I and the protective layer 3, this layer is above The cover layer 5 is removed, and the removal of the material for recycling ends with the selective etching of the upper cover layer 5 relative to the protective layer 3 and / or the selective etching of the protective layer 3 relative to the interlayer 8. 5 According to the present invention After the donor wafer 10 is recovered, A method of removing a useful layer is operated. Therefore, in the advantageous context of the present invention, the cyclic method of removing a useful layer from a donor wafer 10 according to the present invention is performed by repeating the following tasks smoothly and successfully: 10 • a Removal mode; and • a recovery method according to the present invention. Prior to operating the cyclic removal method, it is possible to implement a method for generating a donor wafer 10 using one or more of the techniques described above for generating a thin layer on a substrate according to the present invention. 15 In the remainder of this document, we provide several examples of the configuration of a donor wafer 10 that includes a buffer structure I and can be operated by a method according to the present invention. In particular, we will provide several types of printed materials that can be used to advantage for such donor wafers. 20 As we can see, the buffer structure I with the first lattice parameter generated on the substrate 1 has the main function of having the second lattice parameter on its free surface most of the time. This buffer structure I then contains a buffer layer 2 which may produce such matched lattice parameters. -41- This paper size applies Chinese National Standard (CNS) A4 (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (40) The technology most commonly used to obtain the buffer layer 2 with this characteristic is to use Has a buffer layer 2 composed of several atomic elements, including: • at least one atomic element, which will be in the composition of the substrate 1; and • at least one atomic element, which will be completely or very rarely on the substrate 1 5 has a concentration that gradually changes within the thickness of the buffer layer 2. The progressive concentration of such elements in the buffer layer 2 will be the main reason for the gradual change of the lattice parameters in the buffer layer 2 in a modified manner. Therefore, in this configuration, the buffer layer 2 will be mainly an alloy. The atomic element selected for the composition of the substrate 1 and the buffer layer 2 may belong to Group IV, such as Si or Ge. For example, in this case, it is possible to have a substrate 1 composed of Si and a buffer layer 2 composed of SiGe, where the Ge concentration is a function of a value close to 0 at the interface with the substrate 1 and a buffer The thickness between specific values on the other side of layer 2 changes gradually. 15 In another embodiment, the composition of the substrate 1 and the buffer layer 2 may include an atomic element pair of a group III-V, such as a possible (Al, Ga, In)-(N, P, As) combination. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. For example, in this case, it may have a substrate 1 composed of AsGa and a buffer layer 2 containing As and / or Ga and at least one other element. 20 The at least one other The element system changes gradually with a thickness between a value close to 0 on the interface with the substrate 1 and a specific value on the other side of the buffer layer 2. The composition of the substrate 1 and the buffer layer 2 may include a pair of atomic elements of group II-VI, for example, possible combinations of (Zn, Cd)-(S, Se, Te). -42- This paper size is in accordance with China National Standard (CNS) A4 (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (41) Below, we provide some examples of this configuration: The first three examples are especially about the donor crystal Circle 10 includes a substrate 1 made of si, a buffer layer 2 made of SiGe, and other layers of Si and SiGe. 5 These wafers are particularly useful when removing strained SiGe and / or Si layers to produce SGOI, SOI, or Si / SGOI structures. In this context, the type of etching solution used varies depending on the material (Si or SiGe) to be etched. Therefore, it is possible to engrav these materials; “Guye” will be divided into several categories by assigning the identification numbers included in the following table to each category: • SI: the selectivity of Si over SiGe Etching solution, for example, a solution containing at least one of the following compounds: K0H, NHUOH (ammonium hydroxide), TMAH, EDP, or HNO3, or combinations currently under study such as hno3, hno2h2o2, HF, h2so4, h2so2, ch3cooh, h2o2 15 and Ηβ reagent solution, as described in document WO99 / 53539 page 9. • S2 · SiGe is a selective solution of Si relative to Si, for example, it contains HF: H202: CH3C00H (selectivity of about 1: 1000) or HNA (Hydrogen-nitrogen- Vinegar solution). 20 · Scl: a selective coin solution of SiGe having a Ge concentration of substantially less than or equal to 20% relative to SiGe having a Ge concentration of approximately 25% or more, such as a solution containing TMAH or KOH. • Sdl · Selective etching solution of undoped Si relative to Si doped with rotten (better than 2 X 1019 cm3 butterfly), for example, containing EDP (ethylene-43- This paper size applies to Chinese national standards (CNS) A4 size (210x297 mm) _ 200414417 A7 B7 V. Description of the invention (42) Amine catechol), KOH or N2H2 (hydrazine) solution. Example 1: After recovery, the donor wafer 10 includes:-a substrate 1 'composed of Si,-a buffer structure I, composed of SiGe, having a buffer layer 2 and an additional layer 4;-a The removed layer 7 is composed of Si or SiGe, and after removing a part of the upper cover layer 5, the rest of the upper cover layer 5 is formed. The buffer layer 2 preferably has a Ge concentration which gradually increases from the interface with the substrate 1, so that the SiGe lattice parameter is changed as described above. 10 The thickness is generally between 1 and 3 // m, in order to obtain good structural relaxation of the surface, and contains defects related to differences in lattice parameters. These defects cannot be hidden. The additional layer 4 is composed of SiGe which is substantially relaxed by the buffer layer 2. The Ge concentration is preferably uniform and substantially equal to the Ge concentration of the buffer layer 2 near the interface. The concentration of germanium in the silicon in the relaxed SiGe layer 4 is generally between 15% and 30%. Printed by the Consumer Property Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. This limitation of 30% indicates the general limitation of current technology, but it may change in the next few years. 20 The additional layer 4 has a thickness that can vary greatly depending on the situation, and is typically between 0.5 and 1 micron. In the case where the removed layer 7 is made of Si, the selective etching of Si with respect to the additional layer 4 made of SiGe is preferably performed using an S1 type etching solution in order to remove it. -44- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 x 297 mm) 200414417 A7 B7 V. Description of the invention (43) Under the condition that the removed layer 7 is composed of SiGe and meets the following conditions :-Ge concentration in layer 7 after removal is substantially less than or equal to 20%, and 5-Ge concentration in additional layer 4 is approximately equal to or greater than 25%, selective etching of the removed layer relative to the additional SiGe layer 4 It will be operated with Scl type etching solution in order to remove it. In all cases, the last part of the layer 7 after removal is further used for the etch stop of the protective layer 3, which thus forms the stop layer, and is completely removed by the chemical means 10 to protect the lower layer that we wish to keep. Example 2: After recovery, the donor wafer 10 is substantially the same as the donor wafer 10 provided in Example 1, except that the protective layer 3 exists in the wafer 10. The protective layer 3 contains: 15-strained Si; or-SiGe; or-doped Si. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. We will remember that under the condition that the protective layer 3 is composed of strained Si, the thickness of the protective layer 3 must not exceed the critical thickness here. 20 Thus, for example, for a protective layer 3 composed of strained Si and interposed between two SiGe layers each having a Ge concentration substantially equal to 20%, the critical thickness is generally equal to about 20 nm. In the first case, the protective layer 3 is located between two SiGe layers. The protective layer 3 is located between the two layers of the buffer structure I; or in the buffer structure • 45- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 200414417 A7 B7 Employees of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Consumer Cooperative V. Invention Description (44) I and the removed layer 7 made of SiGe; or in the removed layer made of SiGe, this is especially the case. Therefore, several types of etching can be performed depending on the material of the protective layer 3:-If the protective layer 3 is composed of strained Si: 5 The upper covering portion composed of SiGe is selectively etched with a solution of S2 type ; And / or after the removed layer 7 has been removed, the protective layer 3 is a solution of type S1 and is subjected to a selective remainder. If the protective layer 3 is composed of SiGe having a Ge concentration of about 10% or more, and if the upper cover layer has a Ge concentration of substantially less than or equal to 20%: The part of the upper cover SiGe is of Scl type The solution is subjected to selective etching. -If the protective layer 3 is composed of SiGe having a Ge 15 concentration substantially less than or equal to 20%, and if the lower layer has a Ge concentration approximately equal to or greater than 25%: after the removed layer 7 has been removed, The protective layer 3 is selectively engraved with a solution of Scl type. In the second case, the protective layer 3 is located between the underlying SiGe layer and the overlying Si layer. If the protective layer 3 is located between the buffer structure I and the post-removed Si layer 7; or between the SiGe interlayer 8 and the post-removed Si layer 7; or in the post-removed layer 7 between the SiGe layer and the Si layer, This is particularly the case. Next, several types of etching can be performed according to the material of the protective layer 3; -46- This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm)

200414417 A7 B7 V. Description of the invention (45-If the protective layer 3 is composed of B-doped Si: The overlying 盍 Si 邛 system is selectively etched with an sdl type solution;-if the protective layer 3 If it is made of SiGe: The part of 5 that covers Sl is selectively etched as a solution of type S1.-If the protective layer 3 is made of SiGe with a & concentration that is substantially less than or equal to 20%, and If the lower layer has a Ge concentration approximately equal to or greater than: After the removed layer 7 has been removed, the protective layer 3 is selectively etched with a Sci type 10 solution. In the second case, the protective layer 3 is located at Between two layers. If the protective layer 3 is located between the Si interlayer and the post-removed Si layer 7, or in the post-removed Si layer 7, this is particularly the case. Then, several types of etching can be based on protection The material of layer 3 is operated:-If the protective layer 3 is composed of B-doped Si: The part of the upper cover Si is selectively etched with a solution of Sdl type. 15 Printed-if protective layer 3 is made of SiGe Composition: The overlying Si part is selectively engraved with a solution of type S1; 20 and / or after the removed layer 7 has been removed, the protective layer 3 is selectively etched with a solution of type s2 Example 3: After recycling, the donor wafer 10 includes:-a Si substrate 1; -47- This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 V. Description of the invention (46) -A buffer structure I having one of a SiGe buffer layer 2 and a Ge additional layer 4;-a removed AsGa layer 7, which forms the rest of the upper cover layer 5 after removing a portion of the upper cover layer 5; 5 -An AlGaAs protective layer 3 is provided in the removed layer 7. The buffer layer 2 preferably has a Ge concentration which is gradually increased from the interface with the substrate 1, so that the lattice parameter is in the lattice parameter of the Si substrate 1. And the lattice parameter of the Ge additional layer 4. For this purpose, in the buffer layer 2, the Ge concentration is made from about 10 to about 100%, or more precisely about 98%, In order to make the theoretical lattice of the two materials exactly the same. Selective chemical etching of the removed layer 7 with a selective etching solution makes it possible to substantially remove all of the remaining removed layer 7. The protective layer 3 functions like an etch stop layer. The selective etching The 15-minute solution is, for example, a solution containing citric acid (C6H807) and hydrogen peroxide (selectivity coefficient is generally 20) having a pH value between about 6 and 7. The consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs printed on the second In the solution, after removing a part of the removed layer 7 covering the protective layer 3, and for the aluminum concentration in the protective layer 3 greater than 20%, the protective layer 3 is selectively chemically etched with a selective etching solution. It makes it possible to remove all the protective layers 3 on the actual 20, and the following removed layer 7 acts like an etch stop layer. The selective etching solution contains, for example, diluted hydrofluoric acid (about 9%). And 48%) (the selectivity coefficient is generally between 350 and 10,000). In the third solution, the two selective etchings may be successfully completed with each other. -48- This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 V. Description of the invention (47) for removal At least a part of the layer 7 is removed and the protective layer 3 is removed. The buffer structure I is then retained and completely recovered. Example 4: After recycling, the donor wafer 10 includes:-a substrate 1 including at least a 5 AsGa portion at its interface with the buffer structure I;-at least a portion of the buffer structure I composed of III-V material; -A layer 7 after removal, comprising III-V material, which constitutes the rest of the upper cover layer 5 after removing a part of the upper cover layer 5. The main benefit of this cushioning structure I is used to make the lattice parameters of the material of the upper cover 5 (the nominal value is about 5.87 angstroms) and the lattice parameters of the material of AsGa (the nominal value is about 5.65) E) match. In overall III-V materials, and by comparing overall InP and overall AsGa, AsGa is less expensive, is more widely available in the semiconductor market, and has less mechanical fragility. It is a more well-known method that uses back contact technology. 15 materials, and their size can reach high values (for the overall InP, it is generally 6 α inches instead of 4 σ inches). Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. Therefore, all the benefits provided by such donor wafers 10 can be seen here: This is because it allows the manufacturing to transfer the specific quality and specific characteristics (such as access to 20) III-V material active layer becomes possible. In a special configuration of the donor wafer 10 before removal, the cover layer 5 above the before removal includes the InP to be removed. Because the overall InP has a size that is roughly limited to 4 inches, the donor wafer 10 provides, for example, a solution for manufacturing an InP layer with a size of 6 inches. -49- This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 200414417 A7 B7 V. Description of Invention (48) Law. The buffer structure I used to produce such an upper cover layer 5 needs to have a thickness generally greater than 1 micron, especially if it can be recycled according to the present invention, it will be made to change towards a greater thickness. 5 The epitaxial growth technology system, which is usually operated to produce such a buffer structure I, is also particularly difficult and responsible, so it is advantageous to be able to restore the useful layer at least partially after removal. Advantageously, the buffer structure I includes a buffer layer 2 composed of InGaAs, where the In concentration varies between 0 and about 53%.

10 The buffer structure I may further include an additional layer 4 composed of a III-V material such as InGaAs or InAlAs, which has a substantially constant concentration of atomic elements. In a special removal situation, a part of the cover layer 5 and the additional layer 4 above the InP will be removed in order to transfer it to the receiving substrate. 15 Therefore, it would be possible to benefit from any electrical or electronic characteristics that exist between the two removal materials. The printing situation of the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs is, for example, if one of the removed additional layers 4 is composed of InGaAs or InAlAs: the discontinuity of the electronic frequency band between the InAlAs material and InP will be established. Improved electron mobility in the ablation layer. 20 Other configurations of donor wafer 10 may include other III-V compounds (such as InAlAs, etc.). The typical application of this layer removal is the production of HEMT or HBT (respectively "high electron mobility transistor" and "heterojunction bipolar transistor"). Suitable for removing certain III-V materials relative to other III-V materials The choice of V material -50- This paper size applies Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A7 B7 5. The chemical etching solution of the invention description (49) will preferably be during the first recovery step Is used. Therefore, for example, in order to remove the InP-removed layer 7 without removing the underlying InGaAs layer, the selective etching of InP will preferably operate with a solution containing concentrated HC1. 5 Examples 5: After recycling, the donor wafer 10 contains:-a substrate 1 containing AsGa at its interface with the buffer structure I;-a buffer structure I containing InGaAs at its interface with the layer 7 after removal;- An InP-removed layer 7 that forms the rest of the upper cover layer 5 after removing a part of the upper cover layer 10;-a protective layer 3, which is composed of InxGa ^ xASyP ^ y, is provided after the removal Between layer 7 and cushioning structure I; or after removal 7. This type of donor wafer 10 (without the protective layer 3) has been described in Example 4. 15 In the first scheme, after selective chemical etching is removed with a selective etching solution (such as a solution containing HF), The layer 7 will make it possible to actually remove all the remaining layer 7 after removal, and the protective layer 3 acts like an etch stop layer. The employee consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs printed this in the second scheme. After a portion of the removed layer 20 7 covering the protective layer 3 is removed, the selective chemical etching of the protective layer 3 with a selective etching solution (such as a solution containing CeIVH2S04) will substantially remove all the protective layers 3 becomes possible, and the layer below the protective layer 3 acts like an etch stop layer. In the third solution, the two selective etchings may be successfully completed with each other, -51- This paper size applies Chinese national standards ( CNS) A4 specification (210 X 297 mm) 200414417 A7 ----- B7 V. Description of the invention (50) In order to remove at least a part of the layer 7 after removal and remove the protective layer 3. The buffer structure I is further protected Example 6: After recycling, the donor wafer 10 includes: • a substrate 1 containing AsGa at its interface with the buffer structure I; 5-a buffer structure I containing InGaAs;

InP compliance layer 3 is located on or in InGaAs. In the first scenario, selective chemical etching of the InGaAs overlying the protective layer 3 with a selective etching solution (such as a solution containing CeIVH2S04) will make it possible to virtually remove all such materials overlying the protective layer 3. In this way, the layer 3 of the 10th layer acts like an etch stop layer. In the second solution, after the In (} aAs covering the protective layer 3 is removed, the protective layer 3 is selectively chemically etched with a selective etching solution (such as a solution containing HF), so that virtually all of the plutonium is removed. Layer 3 becomes possible, and the InGaAs located below the compliant layer 3 acts as if the last name is engraved on layer 15. In the second scheme, two selective etchings may be successfully completed to each other in order to remove a part of InGaAs and Remove protective layer 3. Other semiconductor components may be added to the semiconductor layers proposed by the Intellectual Property Bureau employee consumer cooperative printed by the Ministry of Economic Affairs, which may be substantially less than or 20 in the layer in question. Carbon concentration equal to 50% or especially carbon having a concentration of less than or equal to 5%. Finally, the present invention is not limited to a cushioning structure composed of the materials provided in the above examples; [, the middle layer 8 or the upper cover Layer 5, but also extends to other types of alloys (IV-IV, III-V, II-VI types). It should be specifically stated that these alloys can be binary, ternary, -52- 200414417 A7 B7 five ',hair Note (51) or higher grade materials. The present invention is not limited to a recyclable buffer layer 2 having the main function of matching the lattice parameters between two adjacent structures with different individual lattice parameters 2 Or buffer structure I, but also about any buffer layer 2 or buffer structure I that is defined in the most common way in this document 5 and can be recycled according to the present invention. The structure finally obtained after removal is not limited to SGOI, SOI, Si / SG〇I structures, or structures for HEMT and HBT transistors. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs This paper is printed in accordance with China National Standard (CNS) A4 (210 X 297 mm) ) 200414417 A7 B7 V. Description of the invention (52 Brief description of the figure) Figure 1 shows the donor wafer according to the conventional technology. Figure 2 shows the donor wafer after removal. Figure 3 shows the donor wafer after the first recovery step. Figure 4 shows a first donor wafer according to the present invention. Figure 5 shows a second donor wafer according to the present invention. Figure 6 shows a third donor wafer according to the present invention. Figure 7 shows various steps of the method according to the present invention. The sequence includes removing a thin layer from a donor wafer and recovering the donor wafer after removal. 10 15 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs [Code description of the drawing I ~ Buffer structure 1 ~ Substrate 2 '~ Lower 4 ~ Additional layer 5 ~ Upper cover layer 6 ~ Receiving substrate 7 a ~ Raised portion 8 ~ Interlayer Γ ~ Residual portion of buffer structure 2 ~ Buffer layer 3 ~ Protective layer 4, ~ Upper 5f ~ Upper cover layer 7 ~ Removal The subsequent layer 7b ~ rough parts 10, 10 ', 10'f, 10, " ~ donor wafer. 54- This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm)

Claims (1)

200414417 A8 B8 C8 _D8__ VI. Scope of patent application 1. A method for recovering donor wafers (10) after removing at least one useful layer of material selected from semiconductor materials, the donor wafers (10) are sequentially packed. Substrate (1), a buffer structure, and one of the useful layers before removal. The method includes removing the material on the side of the donor wafer (10) from which removal has occurred. 5 It is characterized in that after removing the material, the buffer At least a part of the structure 会 will remain, and at least a part of the buffer structure (Γ) can then be removed at a later useful layer and used as a buffer structure (I). 2. The recovery method as described in item 1 of the scope of patent application, characterized in that: before removal, the buffer structure (I) includes a buffer layer (2) and an additional layer (4), 10 the additional layer ( 4) It has: a thickness large enough to contain defects; and / or a surface lattice parameter substantially different from the lattice parameter of the substrate (1). 3. The recovery method as described in item 1 or 2 of the scope of patent application, characterized in that the removal of the substance includes the removal of a part of the buffer structure 残留 remaining after removal. 4. The recovery method according to item 2 of the scope of patent application, characterized in that the removal of the substance includes the removal of at least a part of the additional layer (4) remaining after removal. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. The recovery method as described in item 1 or 4 of the scope of patent application, characterized in that the removal of the substance includes the removal of a part of the buffer layer (2). 6. The recycling method according to one of the items 1 to 5 of the scope of patent application, characterized in that before the removal, the donor wafer (10) includes an upper cover layer (5), and the upper cover The layer (5) contains useful layers to be removed; and the removal of the material after removal includes the removal of the remaining upper cover layer (5). This paper size applies to the Chinese National Standard (CNS) A4 specification (210 x 297 mm) 200414417 A8 B8 C8 __D8__ VI. Application for patent scope 7. The recycling method described in item 6 of the scope of patent application has the following characteristics: The thickness of the cover layer (5), after removal, can be used on the upper cover layer (5) during the removal of the material using standard mechanical means such as polishing means to remove the material without removing the buffer. Structure (I) 5 things removed. 8. The recycling method as described in item 2 and 6 of the scope of patent application, characterized in that the thickness of the upper cover layer (5) and the thickness of the additional layer (4) have been selected, and can not be used to remove it after removal. Standard mechanical means of matter, such as polishing means, can operate on this upper cover (5) and on this additional layer (4) during the removal of matter without removing matter from the buffer layer (2) . 9. The recovery method as described in one of claims 1 to 8, wherein the removal of the substance includes chemical etching. 10. The recycling method according to one of the items 1 to 9 of the scope of patent application, characterized in that removing the substance from the donor wafer (10) includes selective chemical 15 etching. 11. The recycling method as described in item 2 of the scope of the patent application, characterized in that the removal of the substance from the donor wafer (10) contains at least a portion of the additional layer (4) relative to the buffer layer (2). Selective chemical engraving of materials. Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 12. The recycling method described in item 6 of the scope of patent application, characterized in 20: removing material from the donor wafer (10) contains Selective chemical etching of the first material in the remaining upper cover layer (5). 13. The recycling method as described in item 12 of the scope of patent application, characterized in that the donor wafer (10) includes: a substrate (1) of Si; -56-This paper size is applicable to China National Standard (CNS) A4 specifications (210x297 mm) 200414417 A8 B8 C8 D8 VI. Patent application buffer structure ⑴, including a Sii_xGex buffer layer (2), Ge concentration X increases with thickness between 0 and a y value, and borrows the buffer layer (2) One slack layer (4). 14. The recycling method as described in item 13 of the scope of patent application in combination with one of items 6 to 85 of the scope of patent application, wherein the upper cover layer (5) comprises SiGe and / or strained Si. 15. The recovery method as described in item 13 of the scope of patent application combined with one of the scope of patent applications 6 to 8, characterized in that: y 2 1; and the upper cover layer (5) contains AsGa and / or Ge . 10 16. The recycling method according to item 1 of the scope of patent application, characterized in that: a protective layer (3) is further present in the donor wafer (10), which can enable at least a part of the buffer structure (I) Underneath it; the material of the protective layer (3) is selected from the crystalline material to have the ability to etch by using the method of removing the substance, so that the selective removal of the substance can be manipulated, wherein the etching ability has a protective effect on the protective layer (3) 15 The materials and the materials of at least one of the two adjacent zones are substantially different. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 17. The recycling method described in item 16 of the scope of patent application, characterized by: the nominal lattice parameter of the material of the protective layer (3) and its underlying lattice parameter Different; and the protective layer (3) is thin enough to generate the main elastic strain by the underlying layer. 18. The recycling method according to one of the items 16 and 17 of the scope of patent application, characterized in that the protective layer (3) is in the buffer structure (I). 19. The recovery method according to item 16 or 17 and item 2 of the patent application scope, characterized in that the protective layer (3) is in the buffer layer (2). -57-This paper size applies the Chinese National Standard (CNS) A4 specification (210 x 297 mm). Method 0. The recycling door as described in the 16th or 17th and 2nd patent scope of the patent, its features are ... The layer (3) is between the buffer layer (2) and the additional layer, 21 · As described in the 16th or 17th and 2nd patent scope of Shenyan, the recovery is as follows: · Protective layer (3) In the additional layer (4). 22. The method according to one of the claims 16 and 17 is characterized in that the protective layer (3) is located on the buffer structure ⑴. 23. The recovery method as described in item 22 of the scope of patent application, characterized in that the operation of selective removal of the material that is overlaid on the protective layer (3), the protective layer (3) "Movement of matter" is thus the "stop layer." Back to 4. As described in one of the 22 and 23 of the May patent scope. The method is characterized by the selectivity of the material of the protective layer (3). The removed area is a stop layer for the removal of the substance. The σ-receiving method described in one of the 23 and 24 patent claims states that it is characterized by ... The selective removal of substances in or near the protective layer 包含 includes selective mechanical invasion. The material of the protective layer 选取 is selected from crystalline materials to make the mechanical means invasive, so that the selective machine can be operated. The invasion of rice is essentially different for the materials of Baoxian (3) and the materials of at least one of the two adjacent zones. 26. The recycling method described in item 25 of the scope of patent application, It is characterized by the choice of the Bio-Machinery Zhiyu system as a possibility and grinding and / Polishing combined with chemical money. 27. The recycling method as described in one of the items 23 and 24 of the scope of application for patent, characterized by 200414417 A8 B8 in the protective layer ⑺ or the place near the protective layer ⑺ C8 _D8__ VI. Patent application Selective removal includes selective chemical etching; the material of the protective layer (3) is selected from crystalline materials so that an etching fluid has the ability to erode, so it can operate selective etching, where the erosion The capacity is substantially different for the material of the protective layer (3) and the material of at least one of the two zones adjacent to the protective layer (3). 28. The recycling method described in item 27 of the scope of patent application, It is characterized in that the mechanical erosion of the protective layer (3) operates in combination with selective chemical etching, and can not achieve selective chemical mechanical planarization. 29. For example, the scope of application for patent 28 or the scope of applications for patent 10 to 12 10 The recycling method according to one of the items, wherein the etching selectivity between the material to be etched and the stop material etched by the "stop" is determined by using the Specific etching chemistry and obtained by the fact that two materials are different; or one of the two materials is doped with impurities; or 15 the two materials are substantially the same, but At least one atomic element has an atomic concentration different from that of the same atomic element in another material; or the two materials have different porosity densities. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 30. The recycling method as described in item 29 of the scope of patent application, characterized by 20: the engraved material and the stop material are one of the following dual material groups: Money engraved material stopper material Si doped Si Si SiGe -59-This paper size applies to Chinese National Standard (CNS) A4 specification (210 x 297 mm) 200414417 A8 B8 C8 _D8, patent application scope SiGe Si Sii.xGex SibyGey, of which y 妾 X 31. The recovery method as described in one of the items 1 to 30 of the patent application scope, characterized in that it further comprises a step of trimming the donor wafer (10) after the step of removing the substance from the donor wafer (10). 10) Surface step. 32. The method of recycling 5 as described in one of the items 1 to 31 of the scope of patent application, characterized in that it further comprises a donor crystal after the material removal step after the step of removing the material from the donor wafer (10). The step of forming a layer on the side of the circle (10) can no longer produce a donor wafer (10). 33. The recycling method as described in one of the scope of patent application No. 32 and the scope of patent applications No. 4 and 5, characterized in that the step of forming a layer is included in the residual portion (Γ) of the buffer structure The action of forming a new part of the cushion structure. 34. The recycling method as described in one of the scope of patent applications 32 and 33 and one of the scope of patent applications 6 to 8, characterized in that the step of forming a layer is included in a donor wafer (10 The action of forming the upper cover layer (5) 15 on) can form at least one new useful layer to be subsequently removed. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 35. The recycling method as described in one of the items 32 to 34 of the scope of patent application, characterized in that the step of forming a layer includes the method according to the 16th scope of the scope of patent application The operation of forming a new protective layer (3) in the donor wafer (10). 36. The method for recycling 20 as described in one of the items 32 to 35 of the scope of patent application, wherein the aforementioned layer is formed by crystal growth during the step of forming the layer. 37. Recycling as described in one of items 1 to 36 of the scope of patent application-60-This paper size applies to Chinese National Standard (CNS) A4 (210 x 297 mm) 200414417 A8 B8 C8 _D8__ VI. Scope of patent application The method is characterized in that the donor wafer (10) includes at least one layer, and the at least one layer further contains carbon having a concentration substantially less than or equal to 50%. 38. The recycling method according to one of the items 1 to 37 of the scope of patent application, characterized in that the donor wafer (10) includes at least one layer, and the at least one layer 5 further contains a concentration of substantially less than or equal to 5%. carbon. 39. A method for generating a donor wafer (10), the donor wafer (10) is intended to provide a useful layer by extraction, and according to the recovery method described in one of the items 16 to 28 of the scope of patent application, the application wafer The bulk wafer (10) can be recovered after being removed, and is characterized in that it includes the following steps: 10-forming the first part (2 ') of the buffer structure ⑴ on the substrate (1); A protective layer (3) made of a material selected from a crystalline material is formed on the first part (2 ') of the);-a second part (4') of the buffer structure (I) is formed on the protective layer (3) so that It has a lattice parameter near the protective layer (3), which is substantially the same as the lattice parameter of the first part (2 ') of the buffer structure (I) near the protective layer (3). . 40. The method for generating a donor wafer (10) as described in item 39 of the scope of the patent application, characterized in that the buffer structure includes: a buffer layer (2) printed by an employee consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs; and 20 an additional The layer (4) has a thickness large enough to contain defects; it is characterized in that the protective layer (3) is formed: in the buffer layer (2), during its formation, or between the buffer layer (2) and the additional layer (4), or in the additional layer (4), during its formation. -61-This paper size is in accordance with the Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A8 B8 C8 _D8_ VI. Patent application scope 41. The donor wafer is generated as described in item 39 or 40 of the patent application scope (10) The method is characterized in that it further comprises forming an upper cover layer (5) on the buffer structure (I) so that at least one useful layer can be formed. 42. — A method for generating a donor wafer (10), which is intended to provide a useful layer by removal, and according to one of the items 16 to 28 of the scope of patent application, the donor wafer ( 10) Can be recovered after removal, characterized in that it includes the following steps:-forming a buffer structure ⑴ on the substrate (1);-forming a protection 10 on the buffer structure 利用 using a material selected from crystalline materials Layer (3);-forming an upper cover layer (5) on the protective layer (3). 43. The method for generating a donor wafer (10) according to one of the items 39 to 42 of the scope of patent application, characterized in that the thickness of the protective layer (3) is controlled during its formation so that all The protective layer (3) formed is thin enough to be substantially elastically strained by the underlying layer. 44. The method for generating a donor wafer (10) according to one of the items 39 to 43 of the scope of patent application, characterized in that the formation of the protective layer (3) is a crystal growth. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 45. The method for generating donor wafers (10) as described in item 44 of the scope of patent application, characterized in that it further includes a doped protective layer (3) to make it into The action of the stopper layer on which the cover material is removed. 46. The method for generating a donor wafer (10) as described in item 44 of the scope of patent application, which is characterized in that it further comprises a porosification of the protective layer (3) so that the lower layer becomes a stop for its removal. Layer operation. -62-This paper size is in accordance with Chinese National Standard (CNS) A4 (210x297 mm) 200414417 A8 B8 C8 D8 6. Application for patent scope 47. — Remove useful layer on donor wafer (10) for transfer to receiver The method of the substrate (6) is characterized in that it comprises: (a) bonding the donor wafer (10) to the receiving substrate (6); (b) bonding the useful layer and the donor wafer (10) to the receiving substrate (6) Divide 5 points; and (c) follow the recovery method described in one of the scope of claims 1 to 38 to recover the donor wafer. 48. The method for removing a useful layer as described in item 47 of the scope of patent application, characterized in that it comprises a step of forming a bonding layer before step (a). 10 49. The method for removing useful layers as described in any one of claims 46 to 48 of the scope of patent application, characterized in that:-it further comprises a donor crystal passing through the adjacent buffer structure (I) before step (a) The surface of the circle (10) is a step of implanting atomic matter at a certain depth so as to form a fragile zone at this depth; and 15-step (b) operates by supplying energy to the donor wafer (10) to facilitate fragility The zone level separates the structure containing the receiving substrate (6) from the useful layer. 50. The method for removing useful layers as described in one of the 48 items in the scope of patent application, characterized by: printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-which is further included before step (a), by Porosification 20 and a step of growing with the layer is formed in the donor wafer (10) (after separation in step (b), it will become a useful layer), and the porosification layer is inside the buffer structure (I) Or forming a fragile zone on the buffer structure (I); and-step (b) is operated by supplying energy to the donor wafer (10), so that the fragile zone level includes the receiving substrate (6) and the useful layer. Constructed separately. -63-This paper size applies to China National Standard (CNS) A4 specification (210x297 mm) 200414417 A8 B8 C8 D8 VI. Application for patent scope 51. Except as described in one of the scope of patent applications 47 to 50 The useful layer method is characterized in that the useful layers separated during step (b) include a part of the buffer structure (I). 52. A method for periodically removing useful layers from a donor wafer (10), which is characterized in that it includes several steps for removing useful layers, each of which follows the steps in the scope of claims 47 to 51 of the patent application The removal method described in one of them. 53. — An application of the periodic removal method as described in item 52 of the scope of the patent application, or an application of the removal method 10 as described in one of the scope of the patent applications 47 to 51 to generate The structure of the substrate (6) and the useful layer, the useful layer includes at least one of the following materials: SiGe, Si, an alloy belonging to the III-V group, and its composition system from (Al, Ga, In)-(N, P, As) The composition selected in combination. 54. An application of the periodic removal method 15 as described in item 52 of the scope of patent application or the removal method as described in one of items 47 to 51 of the scope of patent application to produce a semiconductor with an insulating layer The structure includes a receiving substrate (6) and a useful layer. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 55. A donor wafer 20 (1〇) that can be recovered by the extraction method to provide a useful layer and can be recovered by the method described in one of the patent application items 1 to 38 ), Which is characterized in that it sequentially comprises a residual portion of a substrate (1) and a buffer structure (I). 56. A recoverable donor wafer (10) according to the recovery method described in one of the items 16 to 28 of the scope of application for a patent, characterized in that a protective layer (3) exists in a buffer structure ( I). -64-This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210x297 mm) 200414417 A8 B8 C8 _D8__ f. Patent application scope 57. The donor wafer (10) as described in item 56 of the patent application scope, its characteristics For: before the removal, the buffer structure (I) includes a buffer layer (2) and an additional layer (4), the additional layer (4) having: a thickness large enough to contain defects; and / or 5 substantially the same as the substrate ( 1) Surface lattice parameters with different lattice parameters; and its characteristics are: the protective layer (3) is located in: in the buffer layer (2); or between the buffer layer (2) and the additional layer (4) ; Or 10 in additional layer (4). 58. A recoverable donor wafer (10) that complies with the recovery method as described in one of the items 16 to 28 of the scope of patent application, characterized in that a protective layer (3) is located on the buffer structure ⑴ . 59. The 15-donor wafer (10) according to one of the items 56 to 58 of the scope of patent application, characterized in that it further comprises a cover layer (5) above one of the buffer structures (I), It cannot contain at least one useful layer. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 60. The donor wafer (10) as described in one of the items 56 to 59 of the scope of patent application, characterized in that the protective layer (3) is essentially due to its lower layer Subject to elastic strain. 20 61. The donor wafer (10) according to one of the items 56 to 60 of the patent application scope, characterized in that the protective layer (3) is doped with impurities. 62. The donor wafer (10) according to any one of claims 56 to 61 of the scope of patent application, wherein the protective layer (3) is made of a porous material. -65-This paper size applies to China National Standard (CNS) A4 (210x297 mm)