TWI442510B - Susceptor unit and apparatus for processing substrate using the same - Google Patents

Description

Base unit and device for processing the substrate using the base unit

The present invention relates to a susceptor and a substrate processing apparatus having the same, and more particularly to preventing occurrence of a temperature gradient so as to be uniform with respect to a substrate A susceptor performing heat treatment, and a substrate processing apparatus having the susceptor.

Recently, the use of rapid thermal process (RTP) equipment is increasing as heat treatment is sliced in the manufacture of semiconductors. The RTP device is capable of rapidly heating and cooling the substrate by using a radiation ray radiated from a heat source such as a lamp.

A prior art RTP device has a base unit. The base unit is composed of a substrate handling unit that moves the substrate up and down and a base on which the moved substrate is placed.

According to the prior art, a lift pin is commonly used as a substrate handling unit. The lifting ram is driven up and down via a pin hole formed on the base to place the substrate on the pedestal. A plurality of lifting rams are used to maintain the horizontal position of the substrate moving up and down.

However, since the upper tip of the lifting ram (supporting the lower surface of the substrate) is pointed, the surface of the substrate may be damaged (top rod trace), thereby reducing the yield of the more expensive substrate and reducing the productivity. .

According to the prior art, a cap is coupled to or formed at the pointed upper tip of the lifting ram to prevent such damage to the substrate caused by the upper tip of the lifting ram. The upper surface of the cover is formed into a horizontal plane and makes surface-contact with the lower surface of the substrate. The lifting ram with the lid is also driven up and down via the ram hole formed at the base in the same manner as the lifting ram with the pointed upper tip.

The prior art lifting ram moves downward in the state of supporting the substrate, thereby placing the substrate on the pedestal. Here, since the substrate is placed on the pedestal, the lifting ejector is disposed in the ejector hole. However, in the prior art, since the lifting jack has a diameter smaller than the jack hole for smoothly moving up and down, an empty space is generated in the jack hole in this state.

The blank space reduces the balance of the shape of the pedestal and causes a temperature gradient at the pedestal during the heat treatment of the substrate. Therefore, the heat treatment of the substrate placed on the susceptor is performed unevenly. (Here, the uneven heat treatment result can be proved by the roughness of the substrate surface which varies depending on the area.)

Meanwhile, according to the prior art, since the substrate and the susceptor placed on the susceptor form a surface contact with each other, the degree of close contact during the processing of the substrate is improved. In other words, when the substrate is separated from the susceptor after the substrate is processed, the substrate may be damaged or deformed, thus inducing defects of the substrate.

The present invention provides a base unit and a substrate processing apparatus using the base unit.

The present invention also provides a base unit having a separate type of base to prevent a temperature gradient caused by an imbalance of the shape of the base, and a substrate processing apparatus using the base unit.

The present invention also provides a susceptor unit capable of achieving uniform heat treatment of a substrate by treating a separate susceptor by vacuum adsorption.

According to an exemplary embodiment, the base unit includes: a base divided into a main base, the main base being formed to have a lifting hole vertically penetrating the base body, and a sub base, The sub base is inserted into the lifting hole and engaged with the lifting hole to form a coplanar surface with the upper surface of the main base such that the substrate is placed on the main base and the sub base; and the substrate lifting unit, the substrate lifting unit is suitable for vacuum Pick up and move up and down the sub-base separated from the center of the base.

In accordance with another exemplary embodiment, a substrate processing apparatus includes a chamber adapted to supply a reaction space for processing a substrate, a loading and unloading unit adapted to move the substrate into and out of the reaction space, and a base unit Mounted in the reaction space to mount the substrate received from the loading and unloading unit thereon; and a heating unit installed in the chamber to apply heat to the substrate placed in the reaction space, wherein the base unit comprises: a base The base is divided into a main base formed through a lifting hole vertically penetrating the base body, and a sub-base inserted into the lifting hole and engaged with the lifting hole Forming a coplanar surface with the upper surface of the main base such that the substrate is placed on the main base and the submount; and a substrate lifting unit adapted to vacuum pick up and move the submount separated from the center of the base up and down.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Specific embodiments are described in detail below with reference to the drawings. However, the invention may be embodied in different forms and the invention should not be construed as being limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and the scope of the invention will be fully conveyed by those skilled in the art. The same reference numbers are used throughout the drawings to refer to the same elements.

FIG. 1 is an exploded perspective view of a base unit, according to an exemplary embodiment. Figure 2 is a vertical cross-sectional view of the base unit of Figure 1. Figure 3 is a vertical cross-sectional view of a first modified version of the base unit. 4 is a vertical cross-sectional view of a second modified version of the base unit. Fig. 5 is a view showing an operational state of the base unit.

Referring to FIGS. 1 through 5, the base unit 100 according to an exemplary embodiment includes a susceptor 200 on which a substrate 1 is placed, and a substrate elevating unit 300 adapted to move the substrate 1 onto the susceptor 200.

The base 200 includes a main base 210 formed through a lift hole 212 that vertically penetrates the center of the base body, and a sub susceptor 220 that is inserted into the lift hole 212 and engages with the lifting holes 212, thereby forming a co-planar surface with the upper surface of the main base 210, L ₁ (FIG. 2). When the base 220 engaged with each other with the sub master base 210, i.e., the upper surface of the base when the main upper surface 210 of the submount 220 is formed coplanar surfaces L _1, the substrate 1 is firmly, sat.

The substrate lifting unit 300 vacuum-picks the lower surface of the sub-base 220 and moves the sub-base 220 up and down toward the upper portion of the main base 210 and from the upper portion of the main base 210. Therefore, the substrate lifting unit 300 drives the substrate 1 supported by the sub-base 220 up and down at the upper portion of the susceptor 200.

As mentioned before, the susceptor 200 is divided into a main pedestal 210 and a sub pedestal 220, and is supplied with a position at which the substrate 1 is placed. When the main susceptor 210 is fixed in the substrate processing apparatus 1000 (which will be described in detail with reference to FIG. 6), the sub pedestal 220 is disposed in the elevating hole 212 formed at the main pedestal 210, and is moved up and down by the substrate elevating unit 300. drive.

The main susceptor 210 is formed into a plate having any one of a circular shape, an elliptical shape, a square shape, and other polygonal shapes according to the shape of the substrate 1. In the present embodiment, the main base 210 has a circular plate shape corresponding to the substrate 1 having a circular shape.

Likewise, the submount 220 can be cut from the main pedestal 210 into any of a circular shape, an elliptical shape, a square shape, and other polygonal shapes. In the present embodiment, the submount 220 has a circular plate shape that minimizes a contact area between the main pedestal 210 and the sub pedestal 220.

According to an exemplary embodiment, the submount 220 is cut from the center of the main base 210. Specifically, the center point C ₁ (FIG. 2) of the sub-base 220 and the center point Cs of the main base 220 are disposed on the same vertical line L ₂ . Therefore, the sub-base 220 supports the center of the lower surface of the substrate 1 in contact with the surface of the sub-mount 220. That is, although not supported at a plurality of positions, the lower surface of the substrate 1 can be stably supported.

Although not shown, the embodiment may be modified to form a plurality of sub-bases 220 from the main base 210. In this case, the individual substrate lifting unit 300 drives the sub-base 220 up and down.

A support sidewall 400 may be additionally formed along the circumference of the upper surface of the main susceptor 210 to prevent the substrate 1 from escaping from the placed position and to improve the thermal efficiency of the substrate 1 during the heat treatment of the substrate 1. Since the main base 210 of the present embodiment has a circular plate shape, the support side wall 400 is formed in a ring shape.

As shown in FIG. 2, the height h ₂ of the support side wall 400 surrounding the side surface of the substrate 1 may vary according to the thickness t _{o ' of the} substrate 1. Although the height h _{2 of the} support sidewall 400 may be less than the thickness t _{o ' of the} substrate 1, it is exemplified that the height h ₂ is equal to or greater than the thickness t _{o '} to obtain a more stable support of the side surface.

According to the present embodiment, the thickness t _{1 of the} main susceptor 210 and the thickness of the sub pedestal 220 are formed to be substantially the same to prevent an imbalance of the shape of the susceptor 200. Therefore, when the sub-base 220 is inserted into the elevating hole 212 of the main base 210 and engaged with the elevating hole 212, no empty space is formed in the elevating hole 212. Since the main base 210 and the sub-base 220 have substantially the same thicknesses t ₁ and t ₂ , the upper surface of the main base 210 and the upper surface of the sub-base 220 when the sub-base 220 is fully engaged with the main base 210 A coplanar surface L _{1 is} formed.

The main base 210 and the sub base 220 may be made of the same material. According to the present embodiment, the main susceptor 210 and the sub pedestal 220 are made of graphite, silicon carbide (SiC) coated graphite, or SiC-containing ceramic.

When the main base 210 and the sub-base 220 formed of the same material and having the same thicknesses t ₁ and t ₂ are engaged with each other, the susceptor 200 having a separate structure may have the same function as the integrated pedestal during heat treatment. Therefore, the susceptor 200 is uniformly applied with heat throughout the entire area during the heat treatment, thereby forming a uniform heat distribution. Therefore, not only the substrate 1 placed on the susceptor 200 is uniformly applied with radiant heat from the substrate processing apparatus 1000, but also heat transfer between the substrate 1 and the susceptor 200 is effectively realized. That is, the heat treatment can be uniformly performed in the entire region of the substrate 1.

The sub-base 220 overlaps with the main base 210 by being inserted into the elevating hole 212 formed at the main base 210. In the present embodiment, the base step 214 protrudes inward from the lower inner circumference of the elevating hole 212, and the support step 224 protrudes inward from the upper outer circumference of the sub-base 220. Since the sub-base 220 is inserted into the elevating hole 212, the lower surface of the support step 224 is brought into contact with the upper surface of the base step 214.

The thickness t of the thickness of the substrate 214 step ₃ and t ₄ of the support step 224 may be substantially equal to the sum of the thickness of the main base 210, a thickness t shown in FIG. ₁ or the sub-base 220 t _2, as in the following [Equation 1].

t ₃ + t ₄ = t ₁ or t ₃ + t ₄ = t ₂ ... [Equation 1]

The thickness t _{3 of the} base step 214 and the thickness t _{4 of the} support step 224 can be changed as long as [Equation 1] is satisfied.

Illustratively, the thickness t ₃ of the base step 214 supporting the support step 224 is equal to or greater than the thickness t _{4 of} the support step 224. In the present embodiment, the thicknesses t ₃ and t ₄ are equal, that is, equal to half the thickness t _{1 of the} main susceptor 210 or the thickness t ₂ of the sub pedestal 220.

The protruding length L _{3 of the} base step 214 is substantially equal to the protruding length L _{4 of the} support step 224. The protruding lengths L ₃ and L ₄ are calculated by [Equation 2] below.

L ₃ = L ₄ = (D _{h -} D _o' )/2... [Equation 2]

Wherein D _h represents the diameter of the lifting hole 212 and D _{o '} represents the diameter of the sub-base 220.

When the main base 210 and the sub-base 220 are configured to have the same thicknesses t ₁ and t ₂ , and at the same time, the base step 214 and the support step 224 are configured to have the same protruding lengths L ₃ and L ₄ , the lifting holes 212 The blank space is filled by the base step 214 and the support step 224 because the main base 210 overlaps the sub-base 220. In other words, no blank space is generated in the susceptor 200.

According to a first modified version as shown in FIG. 3, a plurality of recesses 218 and 228 may be formed on the upper surface of the base 200a (more specifically, the upper surface of the main base 210a and the sub-base 220a, respectively). On the upper surface). In this case, the contact area between the substrate 1 and the susceptor 200a in the placed position is minimized, thereby constraining the close contact between the substrate 1 and the susceptor 200a. Furthermore, heat transfer from the susceptor 200a to the substrate 1 can be adjusted by adjusting the dimensions of the recesses 218 and 228.

Here, the recesses 218 and 228 may be formed by sand blasting or shot peening.

According to a second modified version of the embodiment as shown in FIG. 4, the main base 210 can be further divided into a fixed susceptor 240 and a divided susceptor 250. The fixed base 240 supplies a position for supporting the side wall 400 to be disposed on the upper surface of the support side wall 400 along the outer circumference. The fixed base 240 includes a cutout hole 242 that vertically penetrates the center of the base body. The separation base 250 includes a lifting hole 252 that is inserted into and engaged with the lifting hole 252. The separation base 250 is inserted into the cut hole 242 and engaged with the cut hole 242 to form a coplanar surface L ₁ with the upper surface of the fixed base 240. When the susceptor 200b is divided into three or more portions as such, the sub pedestal 220 or the separation pedestal 250 overlapping the sub pedestal 220 can move the substrate 1 according to the size of the substrate 1 placed on the susceptor 200b or up and down. The substrate lifting unit 300 is driven up and down in size.

According to a second modified version, the main base 210 is divided into a fixed base 240 and a separate base 250. However, without being limited thereto, the main base 210 may be divided into two or more separate bases.

The substrate lifting unit 300 that moves the sub-bases 200 and 220a in the susceptors 200, 200a, and 200b will be explained below according to an exemplary embodiment, a first modified version, and a second modified version.

The substrate lifting unit 300 includes an absorbing rod 310, wherein a vacuum picker 312 is opened to a lower surface of the sub-base 220, and a rod elevating unit 320 adapted to drive the absorption rod 310 up and down is provided. And a pump unit 330 adapted to adjust the internal pressure of the absorption rod 310. Additionally, a pressure seal member 340 may be provided at the upper end of the absorbent rod 310 to achieve airtightness between the absorbent rod 310 and the sub-base 220. An O-ring can be used as the pressure sealing member 340.

The diameter D _a ( FIG. 2 ) of the absorption rod 310 is smaller than the diameter D _{o ' of the} sub-base 220. Therefore, as shown in FIG. 5B, when the absorption rod 310 moves upward and supports the lower surface of the sub-base 220, the lower surface of the sub-base 220 completely covers the vacuum pickup 312.

When the upper end of the absorption rod 310 contacts the lower surface of the sub-base 220, the pump unit 330 is driven to form a vacuum P ₂ in the absorption rod 310 such that the sub-base 220 is attached to the absorption rod 310. (Although not shown, a contact sensor or position sensor may be further provided to sense the contact state between the upper end portion of the absorption rod 310 and the sub-base 220.)

Next, as shown in FIG. 5D, when the substrate 1 is placed on the sub-base 220, the rod lifting unit 320 moves the absorption rod 320 downward. When the substrate 1 moved by the sub-mount 220 is placed on the susceptor 200, the pump unit 330 changes the internal pressure of the absorption rod 330 from the vacuum P ₂ to the atmospheric pressure P ₁ . Therefore, the absorption rod 310 is separated from the sub-base 220 (Fig. 5E). Here, since the sub-base 220 downward force is applied until the pressure within the absorber rod 310 becomes the atmospheric pressure up to P _1, the sub-base 220 is inserted spontaneously main base 210 and 210 overlap the main base.

A substrate processing apparatus including a base unit will be explained below according to exemplary embodiments and modified embodiments.

In the following description, a rapid thermal processing (RTP) apparatus is illustrated as an example of a substrate processing apparatus. However, without being limited thereto, the embodiment can be applied to various other substrate processing apparatuses such as a vapor-deposition apparatus, an etching apparatus, and an ashing apparatus.

Also, the substrate processing apparatus according to an exemplary embodiment may use all of the base units according to the exemplary embodiment, the first modified version, and the second modified version. Therefore, the elements that have been explained will simply be explained or not explained.

FIG. 6 is a schematic structural diagram of a substrate processing apparatus according to an exemplary embodiment.

Referring to FIG. 6, the substrate processing apparatus 1000 includes a chamber 1100 that supplies a reaction space S that can heat-treat the substrate 1, a loading and unloading unit 1200 that is adapted to move the substrate 1 into or out of the reaction space S, and is installed in the reaction. The base unit 100 in which the substrate 1 received from the loading and unloading unit 1200 is housed in the space S, and a heating unit 1300 that is mounted in the chamber 1100 to heat the substrate 1 placed in the reaction space S.

The susceptor 100 includes a susceptor 200 and a substrate lifting unit 300 that vacuum picks up and moves the sub pedestal 220 up and down. The base 200 includes a main base 210 formed through a lifting hole 212 vertically penetrating the base body, and a sub-base 220 inserted into the lifting hole 212 and the lifting hole 212 Engaged to be level with the upper surface of the main base 210. The substrate 1 is placed on the main base 210 and the sub-base 220.

A gate 1110 for the passage of the substrate 1 is formed at a side of the chamber 1100 connected to the loading and unloading unit 1200. In addition, the heating unit 1300 installed in the chamber 1100 includes a plurality of lamps 1310 as a heat source. The radiation R is radiated from the lamp 1310 to the substrate 1.

The position of the main base 210 supplied to the substrate processing apparatus 1000 is fixed in the reaction space S. In addition, a support sidewall 400 may be provided along the circumference of the upper surface of the main pedestal 210 to prevent the substrate 1 from escaping and to improve the thermal efficiency of the substrate 1. The position of the main base 210 may be fixed to the reaction space S by a support member (not shown) vertically mounted on the lower inner surface of the chamber 110 or by a protruding member (not shown) formed on the side surface of the chamber 1100. in.

The main base 210 and the sub-base 220 are formed to be substantially the same thickness. When the main base 210 and the sub-base 220 overlap each other, the upper surface of the main base 210 and the upper surface of the sub-base 220 form a coplanar surface. In addition, the lift holes 212 (FIG. 1) of the main base 210 are filled by the sub-base 220 so that no blank space is left in the base 200.

More specifically, the sub-base 220 overlaps the elevating hole 212 of the main base 210 by being inserted into the elevating hole 212. According to the present embodiment, the base step 214 (Fig. 2) protrudes from the lower inner circumference of the elevating hole 212, and the support step 224 protrudes inward from the upper outer circumference of the sub-base 220. Since the sub-base 220 is inserted into the elevating hole 212, the lower surface of the support step 224 is brought into contact with the upper surface of the base step 214.

The plurality of recesses 218 and 228 (FIG. 3) may be formed on an upper surface of the main base 210 and an upper surface of the sub-base 220.

As shown in FIG. 4, the main base 210 can be further divided into a fixed base 240 and a separate base 250.

The substrate lifting unit 300 includes an absorption rod 310, wherein the vacuum pickup 312 is opened to the lower surface of the sub-base 220, a rod lifting unit 320 adapted to move the absorption rod 310 up and down, and a pump adapted to adjust the internal pressure of the absorption rod 310. Unit 330. In addition, a pressure sealing member 340 may be provided to the upper end portion of the absorption rod 310 to obtain airtightness between the absorption rod 310 and the sub-base 220.

According to the base unit of the above embodiment and the substrate processing apparatus having the base unit, the base has a separation structure such that a portion of the separation type base can support the substrate, thereby preventing, for example, a pin mark of the substrate, etc. The surface is damaged.

In addition, the substrate can be stably placed on the susceptor by a portion of the susceptor that is handled by a vacuum adsorption method. In particular, since the center of the susceptor supports the substrate in contact with the surface of the substrate, the substrate can be stably moved up and down although not supported at a plurality of positions.

Since the split type pedestal does not generate a blank space, the occurrence of a temperature gradient of the susceptor can be prevented during the heat treatment.

Therefore, the heat treatment can be uniformly performed to the entire region of the substrate. Therefore, the quality and yield of the substrate are improved. Therefore, the productivity of substrate processing is improved.

By forming a plurality of recesses on the upper surface of the base that is in contact with the lower surface of the substrate placed on the susceptor, the close contact between the substrate and the susceptor can be released.

Therefore, after the heat treatment, the substrate can be separated from the susceptor without causing damage or deformation of the substrate. That is, a defective substrate can be reduced or prevented.

Although the base unit and the substrate processing apparatus have been described with reference to the specific embodiments, they are not limited thereto. Accordingly, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as defined by the appended claims.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100. . . Base unit

200. . . Pedestal

210. . . Main base

212. . . Lifting hole

214. . . Base step

218. . . Recess

220. . . Sub base

224. . . Support step

228. . . Recess

240. . . Fixed base

242. . . Truncated hole

250. . . Separation base

300. . . Substrate lifting unit

310. . . Absorption rod

312. . . Vacuum picker

320. . . Rod lifting unit

330. . . Pump unit

340. . . Pressure sealing component

400. . . Support side wall

FIG. 1 is an exploded perspective view of a base unit, according to an exemplary embodiment.

Figure 2 is a vertical cross-sectional view of the base unit of Figure 1.

Figure 3 is a vertical cross-sectional view of a first modified version of the base unit.

4 is a vertical cross-sectional view of a second modified version of the base unit.

Fig. 5 is a view showing an operational state of the base unit.

FIG. 6 is a schematic structural diagram of a substrate processing apparatus according to an exemplary embodiment.

100. . . Base unit

200. . . Pedestal

210. . . Main base

212. . . Lifting hole

214. . . Base step

220. . . Sub base

224. . . Support step

300. . . Substrate lifting unit

310. . . Absorption rod

312. . . Vacuum picker

320. . . Rod lifting unit

330. . . Pump unit

340. . . Pressure sealing component

400. . . Support side wall

Claims (15)

A base unit includes: a base including a main base and a sub base, the main base being formed to have a lifting hole vertically penetrating the base body, the sub base being inserted into the lifting And engaging with the lifting hole to form a coplanar surface with the upper surface of the main base, wherein the substrate is placed on the main base and the sub base, wherein the main base is divided into fixed a base and a separation base formed to have a cut hole vertically penetrating a center of the base body, the separation base being formed to have the lift hole and inserted into the cut hole And engaging the cut-out hole to form a coplanar surface with the upper surface of the fixed base; and a substrate lifting unit adapted to vacuum pick up and move the sub-base separated from the center of the base Or the separation base. The base unit of claim 1, wherein the main base includes a support side wall formed along a circumference of the upper surface of the main base to prevent escape of the substrate. The base unit of claim 1, wherein the main base and the sub-base have substantially the same thickness. The base unit of claim 1, wherein a plurality of recesses are formed on the upper surface of the main base and an upper surface of the sub-base. The base unit according to any one of claims 1 to 4, wherein the main base includes a base protruding from a lower inner circumference of the lifting hole a bottom step, and the sub-base includes a support step projecting inward from an upper outer circumference of the sub-base, engaging the lift hole and disposed on the base step. The base unit of claim 5, wherein a sum of a thickness of the base step and a thickness of the support step is substantially equal to a thickness of the main base or the sub-base. The base unit of claim 5, wherein the diameter of the lifting hole is substantially equal to a sum of a diameter of the sub-base and a protruding length of the base step or the sub-base The sum of the diameter and the protruding length of the support step. The susceptor unit according to any one of claims 1 to 4, wherein the main susceptor and the sub pedestal are graphite selected from graphite, tantalum carbide (SiC), or Any of a group of ceramic compositions of SiC is made. The base unit according to any one of claims 1 to 4, wherein the substrate lifting unit comprises: an absorption rod, wherein a vacuum pickup is directed to a lower surface of the sub-base or the separation base Opening; a rod lifting unit adapted to drive the absorption rod up and down; and a pump unit adapted to adjust an internal pressure of the absorption rod. The base unit of claim 9, wherein the absorption rod comprises a pressure sealing member formed at an upper end. A substrate processing apparatus comprising: a chamber adapted to supply a reaction space for processing a substrate; a loading and unloading unit adapted to move the substrate into and out of the reaction space; a base unit mounted in the reaction space to enable The substrate received by the loading and unloading unit is placed thereon; and a heating unit mounted in the chamber to apply heat to the substrate placed in the reaction space, characterized in that the base The unit includes a base, the base includes: a main base and a sub base, the main base being formed to have a lifting hole vertically penetrating the base body, the sub base being inserted into the lifting hole And engaging with the lifting hole to form a coplanar surface with the upper surface of the main base such that the substrate is placed on the main base and the sub base, wherein the main base is divided into a fixed base And a separation base formed to have a cut hole vertically penetrating a center of the base body, the separation base being formed to have the lift hole and inserted into the cut hole Engaging with the truncation hole to An upper surface of said fixed base is formed coplanar surfaces; and a substrate elevating unit, which is adapted to move up and down the vacuum pickup, and the center of the base of the sub-base separation or separation of the base. The substrate processing apparatus of claim 11, wherein the main base is fixedly disposed in the reaction space, and includes a support formed along a circumference of the upper surface of the main base Side walls to prevent escape of the substrate. The substrate processing apparatus of claim 11, wherein the main base and the sub-base have substantially the same thickness. The substrate processing apparatus of claim 11, wherein a plurality of recesses are formed on the upper surface of the main base and an upper surface of the sub-base. The substrate processing apparatus of claim 11, wherein the substrate lifting unit comprises: an absorption rod, wherein the vacuum pickup opens to a lower surface of the sub-base or the separation base; a rod lifting unit, It is adapted to drive the absorption rod up and down; and a pump unit adapted to adjust the internal pressure of the absorption rod.