KR101626393B1 - Recycling Substrate Structure Including Strain Compensation Layer, Making Method Therefor and Device Manufacturing Method - Google Patents

Abstract

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a substrate; A sacrificial layer growth step of growing a sacrificial layer having a lattice constant different from that of the substrate on the substrate; A compensation layer growth step of growing a compensation layer on the sacrificial layer having a stress state opposite to a tense state between the substrate and the sacrificial layer, and a device layer formation step of growing an element layer on the compensation layer; The method comprising the steps of:
According to the present invention as described above, the sacrificial layer can be thickly grown, so that the device can be easily removed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a substrate recycling structure including a strain compensation layer,

The present invention relates to a substrate recycling structure including a strain compensation layer, a structure generating method and a device manufacturing method, and more particularly, to a substrate recycling structure, a structure generating method and a device manufacturing method using a sacrificial layer, A method of fabricating a structure, and a method of fabricating a device including a strain compensation layer that can increase the thickness of a device by further constructing a layer.

Generally, devices are grown on a substrate by equiaxed growth. Since a substrate made of a single crystal is expensive and the device can be used without being located on the grown substrate, techniques for separating the device from the substrate and recycling the substrate have been developed.

A common substrate recycling method is to deposit a sacrificial layer having a similar lattice structure or different chemical properties to the substrate between the substrate and the element and to etch the sacrificial layer to separate the elements. The substrate thus separated is recycled as it is or through a polishing process. In this case, the sacrificial layer is formed in a composition different from that of the substrate or the device, and there may be a difference between the substrate and the lattice constant.

Figure 1 is a diagram illustrating an existing technique for recycling a substrate.

(a) A substrate 10 is prepared. The substrate 10 is preferably a monocrystalline substrate 10 since it is the basis of epitaxial growth.

(b) The sacrificial layer 11 is grown. The sacrificial layer 11 preferably has a crystal structure and a crystal constant similar to those of the substrate 10. However, the sacrificial layer 11 must be etched more easily than the substrate 10 for a particular solvent. At this time, the thicker the sacrificial layer 11, the easier the process is, but the thickness is limited.

(c) The device 12 is grown on the sacrificial layer 11. The element 12 is grown using the same material as the substrate 10, which has no difference in lattice constant, because defects may occur due to the difference in lattice constant.

(d) The sacrificial layer 11 is etched while the element 12 is fixed. The element 12 can be fixed using the second substrate 13 and the sacrificial layer 11 can be fixed with the solvent capable of etching only the sacrificial layer 11 without damaging the substrate 10 and the element 12. [ The element 12 is separated from the substrate 10 by etching. At this time, when the thickness of the sacrificial layer 11 is narrow, it takes a long time because the solvent is hardly penetrated to the middle portion where the etching is finished. In addition, when the sacrificial layer 11 is thin, etching occurs, and cracks tend to occur in the substrate 10 and the element 12 when the element 12 is separated.

(e) When the etching process is completed, the element 12 and the substrate 10 are separated and the substrate 10 is recycled to the substrate 10 of the next growth process.

2 is a graph showing a strain and a stress according to a thickness of a growth layer of a substrate.

Since the substrate 10 and the sacrificial layer 11 have different lattice constants, the sacrificial layer 11 is strained as much as the lattice constant of the substrate 10. Considering the sacrificial layer 11 as an elastic body and calculating the stress through the Young's modulus, it is as shown in (b). The larger the sacrificial layer 11 is, the larger the stress is, as long as there is a difference in the lattice constant. Generally, when AlAs is used as the sacrificial layer 11 for the GaAs substrate 10 and the element 12, a lattice constant difference of about 0.14% is obtained.

Therefore, a general method of recycling the substrate 10 is caused by a difference in lattice constant between the sacrificial layer 11 and the substrate 10, and the strain causes stress. These stresses increase as the particles grow. As a result, when a thin film having a specific thickness or more is grown, stress-induced defects occur when the thin film is grown beyond a critical thickness.

3 is a graph showing a critical thickness according to the ratio of In and Ga when a GaInAs thin film is grown on GaAs.

Since the sizes of In and Ga are different, the lattice constant differs depending on the ratio of In and Ga bonded to As. Thicknesses at which defects start to occur in the thin film are calculated differently according to the calculation formula, but the critical thickness of Ga _{0 .985} In _{0 .015} As with Ga: In of 0.985: 0.015 having the same lattice constant as AlAs is about 3 μm . In other words, when AlAs is used as the sacrificial layer 11, the sacrificial layer 11 can not be grown to 3 m or more.

In other words, when the sacrificial layer 11 having a critical value or more is grown or formed, defects are generated. Therefore, the thickness of the sacrificial layer 11 is limited. Therefore, a long process is required, It grows. Therefore, as the sacrificial layer 11 is larger, it is easier to separate the device 12 and the substrate 10 without damaging the device 12 or the substrate 10, and thus a method is required to reduce the strain while increasing the thickness of the sacrificial layer 11. [

SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure and method for recycling a substrate including a compensating layer for theoretically growing a sacrificial layer having an infinite thickness without defects.

It is another object of the present invention to provide a means for growing a sacrificial layer to be thick, thereby securing the stability of a substrate or a device when the device is separated.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a substrate; A sacrificial layer growth step of growing a sacrificial layer having a lattice constant different from that of the substrate on the substrate; A compensation layer growth step of growing a compensation layer on the sacrificial layer having a stress state opposite to a tense state between the substrate and the sacrificial layer, and a device layer formation step of growing an element layer on the compensation layer; The method comprising the steps of:

Here, when the substrate is GaAs, the sacrificial layer is any one of AlAs and Al _x Ga _(1-x) As (where x is positive number of 1 or less), and the compensating layer is Ga _y In _(1-y) P And GaAs _{yP (1-y)} (y is a positive number of 1 or less).

In the case where the substrate is made of InP, the sacrificial layer is made of In _x Ga _1-x As, In _x Ga _1-x P and In _x Al _1-x As, any one of a, one of the compensation layer is in _y Al _(1-y) As, in _y Ga _(1-y) As and in _y Ga _(1-y) P (stage y is a positive number less than 1) Lt; / RTI >

Here, if the substrate is Ge, the sacrificial layer is _{AlAs, Al x Ga (1-} x) As, In x Ga (1-x) P, GaAs, Ga x As (1-x) P, Al x In ( _1-x) P and Al _x Ga _y In _(1-xy) P wherein x and y are positive numbers and x + y is not more than 1, and the compensation layer is made of AlAs, Al _z Ga _{1 -z) As, Ga z In (} 1-z) P, GaAs, Ga z As (1-z) P, Al z In (1-z) P and _{Al z Ga k In (1-} zk) P ( stage , z and k are positive numbers, and z + k is 1 or less).

Here, the thickness of the sacrificial layer may be 2 nm or more and 1 m or less, and the thickness of the compensation layer may be 2 nm or more and 1 m or less.

Here, the device layer may be a single or multiple junction solar cell.

Here, the sacrificial layer growth step and the compensation layer growth step may be repeated one or more times.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a substrate; A compensation layer growth step of growing a compensation layer having a lattice constant different from that of the substrate; A sacrificial layer growth step of growing a sacrificial layer having a stress state with respect to the substrate opposite to a tension state between the substrate and the compensation layer; and forming an element layer on the sacrificial layer; The method comprising the steps of:

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a substrate; A sacrificial layer growth step of growing a sacrificial layer having a lattice constant different from that of the substrate; A compensating layer growing step of growing a compensating layer having a stress state opposite to a stress state between the substrate and the sacrificial layer; An element layer forming step of growing an element layer on the compensation layer; A bonding step of bonding a second substrate to the element layer; Etching the sacrificial layer; A transfer step of removing the second substrate from the substrate while the element layers are bonded to each other, and a recycling step of recycling the substrate; The method of claim 1, further comprising:

According to another aspect of the present invention, there is provided a semiconductor device comprising: a substrate having a single crystal; A sacrificial layer having a lattice constant different from that of the substrate; A compensating layer for growing a compensating layer having a relaxed state opposite to a tension state between the substrate and the sacrificial layer; and a device layer grown on the sacrificial layer; The present invention provides a recycling structure comprising:

According to the present invention as described above, the sacrificial layer can be thickly grown, so that the device can be easily removed.

In addition, sufficient compensation for strain has the effect of minimizing defects in the device in the device deposition.

Figure 1 is a diagram illustrating an existing technique for recycling a substrate.
2 is a graph showing a strain and a stress according to a thickness of a growth layer of a substrate.
3 is a graph showing a critical thickness according to the ratio of In and Ga when a GaInAs thin film is grown on GaAs.
FIG. 4 is a cross-sectional view illustrating a substrate recycling structure including a compensation layer according to an embodiment of the present invention, and a graph showing stresses and stresses of a sacrifice layer and a compensation layer.
5 is a view illustrating a method of recycling a substrate according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. The structure and operation of the present invention shown in the drawings and described by the drawings are described as at least one embodiment, and the technical ideas and the core structure and operation of the present invention are not limited thereby.

The present invention minimizes the strain existing between the substrate and the device by growing the sacrificial layer so that the lattice constant of the sacrificial layer is different from that of the substrate.

FIG. 4 is a cross-sectional view illustrating a substrate recycling structure including a compensation layer according to an embodiment of the present invention, and a graph showing stresses and stresses of a sacrifice layer and a compensation layer.

The recycling structure includes a substrate 100, a compensation layer 410, a sacrificial layer 110, and a device 120 layer.

The substrate 100 is a single crystal substrate 100 having a single lattice constant K (where K is a constant greater than 0). Since the substrate 100 is a substrate 100 for equiaxed growth, a single crystal is preferable, and since it is a single crystal, it has a single lattice constant.

The sacrificial layer 110 is equiaxed on the substrate 100 and is easily etched into a solvent that does not etch the substrate 100 and has a lattice constant L greater or less than the lattice constant K. The sacrificial layer 110 may be a different composition than the substrate 100 since it is a layer that must later be removed (sacrificed) through etching. Since the reactivity of the sacrificial layer 110 is different from that of the substrate 100, the sacrifice layer 110 may have a different lattice constant. However, the sacrificial layer 110 has a single lattice constant L since it grows on the substrate 100 in an equi-axial direction. In this embodiment, it is assumed that the lattice constant L of the sacrificial layer 110 is larger than the lattice constant K of the substrate 100.

The compensation layer 410 is grown on the sacrificial layer 110 in an equiaxed fashion and is preferably etched into the solvent with the sacrificial layer 110 and has a lattice constant M that is less than or greater than the lattice constant K. The thickness of the compensation layer 410 is preferably such that the strain generated by the sacrificial layer 110 can be compensated. More specifically, if the lattice constant L of the sacrificial layer 110 is greater than the lattice constant K of the substrate 100, then the lattice constant M of the compensation layer 410 is less than K, and if L is less than K, . If the thickness of the sacrificial layer 110 is sufficiently large to cause a large difference in strain, the compensation layer 410 may be made as thick as possible so that the lattice constant at the top of the compensation layer 410 is similar to the lattice constant of the substrate 100 . The tension state between the sacrificial layer 110 and the substrate 100 and the tension between the compensation layer 410 and the substrate 100 are reversed to each other to cancel the stress state will be. In this way, the stress state or strain at the top of the compensating layer 410 becomes zero, so that the lattice constant becomes similar to the substrate 100.

The device 120 layer refers to a substrate 120 that can be printed through a conventional doping process. The device 120 is preferably made of the same material as that of the substrate 100, and is manufactured by growing it on the top of the compensation layer 410 in an equi-axis direction.

In the thus fabricated structure, since L is greater than K in the sacrificial layer 110 based on the lattice constant K of the substrate 100, negative strain exists because M is less than K because positive strain exists.

In the region where the positive strain exists (the sacrificial layer region), the tense state acts in the opposite direction of the strain, but the region where the negative strain exists compensates for the positive strain and the tense state is reduced. In other words, since the sacrificial layer 110 has a lattice constant larger than that of the substrate 100, the sacrificial layer 110 is subjected to a compressive force by the substrate 100. Further, since the compensation layer 410 has a smaller lattice constant than the substrate 100, it receives a tensile force when the device layer is formed. Therefore, the upper part of the compensation layer 410 on which the device 120 layer is formed has a value substantially equal to the lattice constant of the substrate 100. In addition, there is almost no tension in the portion where the device 120 is deposited. Therefore, it is possible to grow the element 120 layer with few defects. At this time, the sacrificial layer 110 does not necessarily have to be in contact with the substrate 100. The compensation layer 410 is first deposited on the substrate 100 and the sacrificial layer 110 is deposited thereon since the sacrificial layer 110 is a means of easily removing the device 120 so that the substrate 100 can be recycled It is also possible to remove the stress. In addition, the sacrificial layer 110-compensating layer 410, which is alternately repeatedly deposited to serve as the sacrificial layer 110, may theoretically be infinitely located.

5 is a view illustrating a method of recycling a substrate according to an embodiment of the present invention.

(a) A substrate 100 is prepared. The substrate 100 is preferably a monocrystalline substrate 100 because it is the basis of epitaxial growth.

(b) The sacrificial layer 110 is grown. The sacrificial layer 110 preferably has a crystal structure and a crystal constant similar to those of the substrate 100. However, since the sacrificial layer 110 is subjected to etching, it must be etched more easily than the substrate 100 with respect to a specific solvent.

(b ') the compensation layer 410 is grown on the sacrificial layer 110. The compensation layer 410 is a layer for compensating for the strain and the stress corresponding to the thickness of the sacrificial layer 110. Thus, the compensating layer 410 is grown with an element having a lattice constant that is opposite to that of the sacrificial layer 110. That is, when the sacrificial layer 110 has a lattice constant larger than that of the substrate 100, the compensation layer 410 takes an element having a smaller lattice constant than that of the substrate 100, and the sacrificial layer 110 has a lattice constant When the constant is small, the compensating layer 410 takes an element having a larger lattice constant than the substrate 100. Each process does not involve any process as long as it can perform epitaxial growth. In other words, techniques such as chemical vapor deposition (CVD), E-beam deposition and the like can be used. As shown in FIG. 2, when the sacrifice layer 110 is larger than 3 μm, defects start to occur. Therefore, the thickness of the sacrifice layer 110 is 2 nm or more and 1 μm or less, ≪ / RTI >

In this case, the substrate may be any one of GaAs and InP. For example, when the substrate is GaAs, the sacrifice layer is any one of AlAs and Al _x Ga _(1-x) As (where x is a positive number of 1 or less) Layer may be any one of Ga _y In _(1-y) P and GaAs _y P _(1-y) (where y is a positive number of 1 or less).

In the case where the substrate is InP, the sacrifice layer is any one of In _x Ga _1-x As, In _x Ga _1-x P and In _x Al _(1-x) As (where x is a positive number of 1 or less) , The compensation layer may be any one of In _y Al _(1-y) As, In _y Ga _(1-y) As and In _y Ga _(1-y) P (where y is a positive number of 1 or less).

There may be a substrate is Ge, In this case, the sacrificial layer is _{AlAs, Al x Ga (1-} x) As, In x Ga (1-x) P, GaAs, Ga x As (1-x) P, Al x In ( _1-x) P and Al _x Ga _y In _(1-xy) P wherein x and y are positive numbers and x + y is not more than 1, and the compensation layer is made of AlAs, Al _z Ga _{1 -z) As, Ga z In (} 1-z) P, GaAs, Ga z As (1-z) P, Al z In (1-z) P and _{Al z Ga k In (1-} zk) P ( stage , z and k are positive numbers, and z + k is 1 or less).

(b) and (b ') may be performed in reverse order. In other words, the compensation layer 410 may generate a reverse stress first and the sacrificial layer 110 may generate a positive stress. Further, the structure in which the sacrificial layer 110 and the compensation layer 410 are repeated may be theoretically infinitely produced by repeating the steps (b) and (b ').

(c) The device 120 is grown on the sacrificial layer 110. The device 120 is grown by using the same material as the substrate 100, which has no difference in lattice constant, because a defect may occur due to a difference in lattice constant. However, it is also possible to generate the element 120 using an element having an appropriate lattice constant according to the compensation relationship of the sacrificial layer 110 and the compensation layer 410.

The device 120 may be a direct transition semiconductor, or may be a single or multiple junction solar cell or photodetector capable of exploiting high light conversion efficiency.

The substrate recycling structure can be manufactured by the above-described method. The substrate can then be recycled through the following steps.

(d) The sacrificial layer 110 is etched while the device 120 is fixed. The device 120 may be fixed using the second substrate 130 and the second substrate 130 may be fixed to the second substrate 130 by an adhesive It may be a thin film of a material. The sacrificial layer 110 is etched with a solvent capable of etching only the sacrificial layer 110 without detaching the substrate 100 and the device 120 to separate the device 120 from the substrate 100. [ At this time, if the sacrificial layer 110 and the compensating layer 410 can be etched in the same solvent, they may be simultaneously etched. In this case, since the etching width is wide, it can be easily etched to the center.

(e) At the end of the etching process, the device 120 and the substrate 100 are separated and the substrate 100 is recycled to the substrate 100 of the next growth process.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Modification is possible.

Accordingly, it is intended that the scope of the invention be defined solely by the claims appended hereto, and that all equivalents or equivalent variations thereof fall within the spirit and scope of the invention.

100: substrate 110: sacrificial layer
120: element 130: second substrate
410: compensation layer

Claims (13)

Board;
A sacrificial layer having a lattice constant different from that of the substrate and different in etch reactivity from the substrate formed on the substrate;
A compensation layer formed on the sacrificial layer and having a tense state opposite to a tense state between the substrate and the sacrificial layer; And
And an element layer formed on the compensation layer,
A compensating layer having a lattice constant different from the substrate and formed on the substrate;
A sacrificial layer having a trench state opposite to a tense state between the substrate and the compensation layer, the sacrifice layer being different in etch reactivity from the substrate formed on the compensation layer; And
And an element layer formed on the sacrificial layer,
M satisfies M <K <L or L <K <M, where K is the lattice constant of the substrate, L is the lattice constant of the sacrificial layer, and M is the lattice constant of the compensation layer,
The sacrifice layer or the compensation layer formed under the device layer is formed to have a thickness capable of compensating for the strain generated by the compensation layer or the sacrifice layer formed under the device layer,
Wherein the element layer corresponding to the uppermost lattice constant of the sacrificial layer or the compensation layer, which is determined according to the compensation relationship of the sacrificial layer or the compensation layer, is formed. delete The method according to claim 1,
Wherein the sacrificial layer and the compensation layer are repeatedly laminated one or more times. The method according to claim 1 or 3,
Wherein the sacrificial layer, the compensating layer, and the element layer are repeatedly laminated one or more times. The method according to claim 1,
Wherein the thickness of the sacrificial layer is 2 nm or more and 1 占 퐉 or less and the thickness of the compensation layer is 2 nm or more and 1 占 퐉 or less. The method according to claim 1,
If the substrate is GaAs and the sacrificial layer is a mixture one or derivatives of AlAs and Al _x Ga _(1-x) As (with the proviso that x is a positive number less than 1), the compensation layer is Ga _y In _(1-y) P and GaAs _{yP (1-y)} (y is a positive number of 1 or less), or a mixture thereof. The method according to claim 1,
In the case where the substrate is InP, the sacrificial layer may be any one of In _x Ga _1-x As, In _x Ga _1-x P and In _x Al _1-x As, one or a mixture thereof, wherein the compensation layer is in _y Al _(1-y) As, in _y Ga _(1-y) As and in _y Ga _(1-y) P (stage y is a positive number less than 1) which of the One or a mixture thereof. The method according to claim 1,
If the substrate is Ge, the sacrificial layer is _{AlAs, Al x Ga (1-} x) As, In x Ga (1-x) P, GaAs, Ga x As (1-x) P, Al x In (1- _x) P and Al _x Ga _y in _(1-xy) P (in this example, x, y is a positive number, and a, x + y is any one or a mixture thereof of 1 or less), the compensation layer is AlAs, Al _z Ga _{( 1-z) As, Ga z} In (1-z) P, GaAs, Ga z As (1-z) P, Al z In (1-z) P and _{Al z Ga k In (1-} zk) P ( And z and k are positive numbers, and z + k is 1 or less), or a mixture thereof. The method according to claim 1,
Wherein the device layer is a single or multiple junction solar cell or photodetector. A substrate preparation step of preparing a substrate;
A compensating layer growing step of growing a compensating layer having a lattice constant different from the substrate on the substrate;
A compensating layer having a thickness that is different from that of the substrate and that is capable of compensating for the strain generated by the compensating layer, A sacrificial layer growth step of growing on the sacrificial layer; And
An element layer forming step of forming an element layer on the sacrificial layer and corresponding to a top lattice constant of the sacrificial layer determined according to a compensation relationship of the sacrificial layer;
Wherein the substrate recycling structure comprises a plurality of substrates. A substrate preparation step of preparing a substrate;
A sacrificial layer growth step of growing a sacrificial layer having a lattice constant different from that of the substrate and different in etch reactivity with the substrate, on the substrate;
A compensating layer growth step of growing a compensating layer having a thickness that is opposite to a tensile state between the substrate and the sacrificial layer and which is capable of compensating for the strain generated by the sacrificial layer on the sacrificial layer;
An element layer forming step of forming an element layer on the compensation layer, the element layer corresponding to a top lattice constant of the compensation layer determined according to a compensation relationship of the compensation layer;
A bonding step of bonding a second substrate to the element layer;
Etching the sacrificial layer;
A transfer step of removing the second substrate from the substrate while the element layer is bonded; And
A recycling step of recycling the substrate;
And forming a second electrode on the second electrode. A substrate having a single crystal;
A sacrificial layer having a lattice constant different from that of the substrate grown on the substrate and different in etch reactivity from the substrate;
A compensating layer having a thickness that is opposite to a tensile state between the substrate and the sacrificial layer grown on the sacrificial layer, the compensating layer having a thickness capable of compensating for strain generated by the sacrificial layer; And
An element layer corresponding to a top lattice constant of the compensation layer determined according to a compensation relationship of the compensation layer, the element layer grown on the compensation layer;
Wherein the substrate is a substrate. A substrate having a single crystal;
A compensating layer having a lattice constant different from that of the substrate grown on the substrate;
A sacrificial layer formed on the compensation layer and having a thickness that is different from that of the substrate and has a thickness capable of compensating for the strain generated by the compensation layer, the sacrificial layer having a stress state opposite to a tension state between the substrate and the compensation layer grown on the compensation layer, ; And
An element layer corresponding to the uppermost lattice constant of the sacrificial layer determined according to the compensation relationship of the sacrificial layer, the element layer grown on the sacrificial layer;
Wherein the substrate is a substrate.

Images