KR102457294B1 - Dome assembly and epitaxial reactor - Google Patents

Abstract

A dome assembly includes a window whose center is convex downward, and a flange for supporting the window. A reference line connecting the lowest point of each of the first and second sides of the flange surrounding the window is defined. A distance between the reference line and the lowest point of the window is defined as a first height. A distance between the reference line and the highest point of the window is defined as a second height. In this case, a ratio of the second height to the first height is 1.15 to 2.25.

Description

Dome assembly and epitaxial reactor

Embodiments relate to dome assemblies and epitaxial reactors.

A typical silicon dome assembly includes a window that is convex in a downward direction at a center and a flange for supporting the window.

A reference line is defined connecting the lowest point of each of the first and second sides of the flange surrounding the window. The distance between the reference line and the lowest point of the window is defined as the first height. The distance between the baseline and the highest point of the window is defined as the second height. In this case, the ratio of the second height to the first height is between 1.15 and 2.25.

A wafer is manufactured through a single crystal growth process, a slicing process, a grinding process, a lapping process, a polishing process, and a cleaning process to remove abrasives or foreign substances attached to the wafer after the polishing process.

A wafer manufactured in this way is called a polished wafer, and a wafer in which another single crystal film (epitaxial layer) is grown on the surface of the polished wafer is called an epitaxial wafer. The epitaxial wafer has fewer defects than the polished wafer, and has characteristics that allow control of the concentration and type of impurities.

The epitaxial layer should be grown to a uniform thickness. However, the thickness of the epitaxial layer varies according to various influences such as the crystal orientation of the wafer, process conditions, and equipment conditions.

When the epitaxial is not uniformly formed as described above, when an electronic device such as a sensor is grown on an epitaxial wafer, the performance of the corresponding electronic device is deteriorated or a defect occurs.

As shown in FIG. 1, even if the epitaxial layer is formed by changing the gas input amount (A, B, C, D, and E), the valley ( V) is formed, and a peak P having the maximum thickness of the epitaxial layer is formed at a position spaced 100 mm from the center. In this case, there is a problem in that the thickness of the epitaxial layer is not uniform because P-V, which is the difference between the valley V and the peak P, is quite large.

The embodiments aim to solve the above and other problems.

Another object of the embodiment is to provide an epitaxial reactor and a dome assembly that allows a uniform epitaxial layer to be grown.

According to one aspect of the embodiment in order to achieve the above or other objects, the dome assembly includes: a window convex in the center downward; and a flange supporting the window. A reference line connecting the lowest points of each of the first and second sides of the flange surrounding the window is defined, a distance between the reference line and the lowest point of the window is defined as a first height, and a distance between the reference line and the highest point of the window When is defined as the second height, the ratio of the second height to the first height is 1.15 to 2.25.

According to another aspect of the embodiment, an epitaxial reactor includes a reaction chamber; a susceptor installed inside the reaction chamber to support a wafer; and a dome assembly disposed on the susceptor. The dome assembly may include: a window having a center convex in a downward direction; and a flange supporting the window. A reference line connecting the lowest points of each of the first and second sides of the flange surrounding the window is defined, a distance between the reference line and the lowest point of the window is defined as a first height, and a distance between the reference line and the highest point of the window When is defined as the second height, the ratio of the second height to the first height is 1.15 to 2.25.

Effects of the dome assembly and the epitaxial reactor according to the embodiment will be described as follows.

According to at least one of the embodiments, by optimizing the structure of the dome assembly by varying the range of the radius of curvature, the first height, and the second height of the window of the embodiment, the flow of the reaction gas flowing into the reaction chamber is controlled to epitaxially. There is an advantage in that the thickness of the seal layer can be made uniform.

Further scope of applicability of embodiments will become apparent from the following detailed description. However, it should be understood that the detailed description and specific embodiments, such as preferred embodiments, are given by way of example only, since various changes and modifications within the spirit and scope of the embodiments may be clearly understood by those skilled in the art.

1 shows the epitaxial film thickness according to the change of the gas input amount.
2 shows an epitaxial reactor according to an embodiment.
Fig. 3 shows the dome assembly of Fig. 2;
4 shows the gas flow in the structure of the epitaxial reactor of the comparative example.
5 shows a gas flow in the structure of an epitaxial reactor according to an embodiment.
6 shows gas flow rates in each of the epitaxial reactor structures according to Comparative Examples and Examples.
7 shows the relationship between H1, H2 and R in the dome assembly of the embodiment.
8 shows the relationship between H1, H2, and PV during epitaxial growth in the epitaxial reactor according to the embodiment.
9 shows a change in the thickness of the epitaxial layer in Comparative Examples and Examples.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to some embodiments described, but may be implemented in various different forms, and within the scope of the technical spirit of the present invention, one or more of the components may be selected between the embodiments. It can be combined and substituted for use. In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be generally understood by those of ordinary skill in the art to which the present invention pertains, unless specifically defined and described explicitly. It may be interpreted as a meaning, and generally used terms such as terms defined in advance may be interpreted in consideration of the contextual meaning of the related art. In addition, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In the present specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when it is described as "at least one (or more than one) of B and (and) C", it can be combined with A, B, and C. It may include one or more of all combinations. In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the component from other components, and are not limited to the essence, order, or order of the component by the term. And, when it is described that a component is 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also with the component It may also include a case of 'connected', 'coupled' or 'connected' due to another element between the other elements. In addition, when it is described as being formed or disposed on "above (above) or under (below)" of each component, the upper (above) or lower (below) is not only when two components are in direct contact with each other, but also one Also includes a case in which another component as described above is formed or disposed between two components. In addition, when expressed as “up (up) or down (down)”, it may include the meaning of not only the upward direction but also the downward direction based on one component.

FIG. 2 shows an epitaxial reactor according to an embodiment, and FIG. 3 shows the dome assembly of FIG. 2 .

Referring to FIG. 2 , the epitaxial reactor 100 according to the embodiment may include a reaction chamber 110 , a susceptor 120 , and a dome assembly 130 .

For example, the epitaxial reactor 100 may be the reaction chamber 110 , and the epitaxial reactor 100 or the reaction chamber 110 may include the susceptor 120 and the dome assembly 130 .

For example, the reaction chamber 110 may be a device for growing an epitaxial layer on the wafer 10 . For example, the reaction chamber 110 may be an overall hardware for growing an epitaxial layer on the wafer 10 .

The susceptor 120 may be installed inside the reaction chamber 110 to support the wafer 10 . The wafer 10 may be seated on the susceptor 120 to grow an epitaxial layer on the wafer 10 . That is, the wafer 10 is loaded into the reaction chamber 110 and seated on the susceptor 120 , and after the epitaxial layer is grown on the wafer 10 , the wafer 10 including the epitaxial layer is unloaded. can be loaded.

For example, the susceptor 120 may be supported by the main shaft 150 .

A lower flange 140 may be disposed around the susceptor 120 .

Meanwhile, the dome assembly 130 may include a window 131 and upper flanges 132 and 133 .

The window 131 may be formed to have a convex center in a downward direction. For example, the thickness of the window 131 in the entire area of the window 131 may be the same, but is not limited thereto.

Since the window 131 has a convex center in the lower direction, the window 131 may have a predetermined radius of curvature R.

As shown in FIG. 3 , the lowest point P1 of the window 131 may be defined at the center, and the highest points P21 and P22 of the window 131 may be defined at the edge. The lowest point P1 may indicate the lowest position in the window 131 , and the highest points P21 and P22 may indicate the highest position in the window 131 .

For example, the window 131 may have a shape having an increasingly higher position from the center to the edge. For example, the position of the window 131 may decrease from one edge to the center, and the position may increase from the center to the other edge of the window 131 .

For example, the window 131 may have a symmetrical structure from the center to the lateral direction. For example, the edges in all regions of the window 131 may have the same position, that is, the highest points P21 and P22, but the present invention is not limited thereto.

The upper flange may include a first upper flange 132 and a second upper flange 133 . The first upper flange 132 and the second upper flange 133 may be integrally formed or separately formed and assembled.

For example, the first upper flange 132 may support the window 131 . For example, the first upper flange 132 may have a ring shape. Accordingly, the window 131 may be fastened to the first upper flange 132 along the circumference of the window 131 .

For example, the second upper flange 133 may surround the first upper flange 132 . For example, the second upper flange 133 may be coupled to the lower flange 140 . For example, the second upper flange 133 may be fixed to the lower flange 140 while supporting the first upper flange 132 .

For example, the reaction space 143 may be formed in the reaction chamber 110 by fastening the second upper flange 133 and the lower flange 140 .

For example, the window 131 may be made of transparent quartz. For example, the first and second upper flanges 133 may be made of opaque quartz, but the present invention is not limited thereto.

A gas inlet 141 may be installed at one side of the reaction chamber 110 , and a gas outlet 142 may be installed at the other side of the reaction chamber 110 . The gas inlet 141 and the gas outlet 142 may be installed to face each other on the same horizontal plane, but the present invention is not limited thereto.

An injection passage 145 may be formed on one side of the reaction chamber 110 , and an exhaust passage 146 may be formed on the other side of the reaction chamber 110 . For example, the injection passage 145 is formed between the lower flange 140 and the second upper flange 133 at one side of the reaction chamber 110 , and the discharge passage 146 is the lower flange at the other side of the reaction chamber 110 . It may be formed between the 140 and the second upper flange 133 .

For example, the injection passage 145 may be connected to the gas inlet 141 and communicated with the reaction space 143 , and the discharge passage 146 may be connected to the gas outlet 142 and communicated with the reaction space 143 . .

For example, a reaction gas injected through gas injection may flow into the injection passage 145 and the susceptor 120 . An epitaxial layer may be grown along the surface of the wafer 10 seated on the susceptor 120 by the reaction gas flowing into the susceptor 120 . The reaction gas passing through the surface of the wafer 10 may be discharged to the gas outlet 142 via the discharge passage 146 .

In this case, the inside of the reaction chamber 110 may be maintained at a temperature suitable for the reaction during the epitaxial growth process by heat emitted from at least two or more heat sources 151 installed below the reaction chamber 110 . The heat source 151 may be a resistance heater, but is not limited thereto.

Meanwhile, while the epitaxial growth process is performed several times, reaction gas residues caused by silicon-based SiCl4, SiHCl3, SiH2Cl2, SiH3Cl and SiH4 are accumulated inside the epitaxial reactor 100 to contaminate the inside of the reaction chamber 110 . can Therefore, after performing the epitaxial growth process, a cleaning process of cleaning the inside of the reaction chamber 110 by injecting a cleaning gas (or etching gas) such as HCl is performed.

The cleaning gas is supplied into the reaction chamber 110 through the gas inlet 40 like the reaction gas while etching the residues of the reaction gas remaining or stacked in the reaction chamber 110 and discharged to the gas outlet 142 while etching. will have

Meanwhile, as shown in FIG. 3 , by optimizing the structure of the dome assembly 130 by varying the radius of curvature R, the first height H1, and the second height H2 of the window 131, the reaction chamber (110) The thickness of the epitaxial layer may be uniform by controlling the flow of the reaction gas flowing therein.

The radius of curvature R of the window 131 may vary depending on the convex shape of the window 131 .

In order to define the first height H1, the reference line 200 must be defined. The reference line 200 may be a line crossing the lowest points P11 and P12 of the first upper flange 132 surrounding the window 131 . For example, when the first upper flange 132 surrounds the window 131, connecting the lowest point P11 on the left side of the first upper flange 132 and the lowest point P12 on the right side of the first upper flange 132, respectively. A line may be defined as the reference line 200 . For example, when the lowest point P11 on the left side of the first upper flange 132 and the lowest point P12 on the right side of the first upper flange 132 are at the same position, the reference line 200 may coincide with a horizontal line.

The first height H1 is defined as a distance between the reference line 200 and the lowest point P1 of the window 131 , and the second height H2 is the highest point P21 and P22 between the reference line 200 and the window 131 . It can be defined as the distance between Accordingly, the first height H1 is the minimum distance at which the window 131 can be positioned closest to the reference line 200 , and the second height H2 is the maximum distance at which the window 131 can be positioned furthest from the reference line. could be the street.

In an embodiment, a ratio of the second height H2 to the first height H1 may be 1.15 to 2.25.

4 shows a gas flow in the structure of the epitaxial reactor of the comparative example, and FIG. 5 shows the gas flow in the structure of the epitaxial reactor according to the embodiment.

4 and 5, wafers 1 and 10 corresponding to 60 mm to 149 mm from the center are shown. Valleys and peaks may form within this numerical range.

4 and 5 , the closer to red, the greater the flow rate of the reactive gas, and the closer to blue, the lower the flow rate of the reactive gas.

4 and 5 , when the reaction gas is supplied into the reaction chamber through the gas inlet, a vortex may be generated at the upper side of the reaction space 143 communicating with the injection passage.

In the comparative example, since a relatively small amount of the reaction gas supplied from the injection passage to the reaction chamber contributes to the vortex, a relatively large amount of the reaction gas flows onto the wafer 1, so that the flow rate of the reaction gas is relatively large (FIG. 4) .

In the embodiment, since a relatively large amount of the reaction gas supplied from the injection passage 145 to the reaction chamber 110 contributes to the vortex, a relatively small amount of the reaction gas flows onto the wafer 10 so that the flow rate of the reaction gas is relatively small (Fig. 5).

As shown in FIG. 6 , it can be seen that the flow rate of the reactive gas in the example is smaller than the flow rate of the reactive gas in the comparative example.

As shown in FIG. 4 , red color is not seen on the left side of the wafer 1 in the comparative example, whereas red color is relatively much seen on the right side, so it can be seen that the difference in the flow rate of the reaction gas is large on the left side and the right side on the wafer 1 . can

As shown in FIG. 5 , red is similarly displayed on the left and right sides of the wafer 10 in the embodiment. Therefore, it can be seen that the difference in the flow rate of the reaction gas between the left and right sides is not large in the embodiment.

As described above, in the embodiment, the flow rate of the reactive gas flowing on the wafer 10 is reduced due to the contribution of many reactive gases to the vortex, so that the reactive gas is uniformly distributed over the entire area of the wafer 10 and the susceptor A uniform epitaxial layer may be grown on the wafer 10 seated on 120 .

7 shows the relationship between H1, H2 and R in the dome assembly of the embodiment.

7 , the first height H1 may be 4 mm to 6 mm. The second height H2 may be 7 mm to 9 mm. The radius of curvature R of the window 131 may be 8,200 mm to 10,300 mm.

For example, the radius of curvature R of the window 131 may depend on the first height H1 and the second height H2 .

For example, when the first height H1 is 4 mm to 6 mm and the second height H2 is 7 mm to 9 mm, the radius of curvature R of the window 131 may be 8,200 mm to 10,300 mm, but limited to this I never do that.

The above-described numerical range may be applied to the wafer 10 having a diameter of 300 mm, but is not limited thereto.

On the other hand, in the epitaxial reactor 100 including the dome assembly 130 having the above-described numerical range, the difference (P-V) between the valley and the peak with respect to the thickness of the epitaxial layer grown on the wafer 10 is 7.5 mm. to 10 mm, but is not limited thereto.

8 shows the relationship between H1, H2, and P-V during epitaxial growth in the epitaxial reactor according to the embodiment.

As shown in FIG. 8 , the first height H1 may be 4 mm to 6 mm. The second height H2 may be 7 mm to 9 mm. The difference (P-V) between the valleys and the peaks for the thickness of the epitaxial layer may be 7.5 mm to 10 mm.

For example, the difference (P-V) between the valleys and the peaks with respect to the thickness of the epitaxial layer may depend on the first height H1 and the second height H2 .

For example, when the first height H1 is 4 mm to 6 mm and the second height H2 is 7 mm to 9 mm, the difference (P-V) between the valley and the peak for the thickness of the epitaxial layer may be 7.5 mm to 10 mm, but , but is not limited thereto.

The above-described numerical range may be applied to the wafer 10 having a diameter of 300 mm, but is not limited thereto.

9 shows a change in the thickness of the epitaxial layer in Comparative Examples and Examples.

As shown in FIG. 9, the valley in the example is much higher than the valley in the comparative example at a position 50 mm apart from the center of the wafer, and at a position 90 mm apart from the center of the wafer, the peak of the epitaxial layer in the comparative example The peak of the epitaxial layer in the example is much lower. Therefore, it can be seen that the difference (P2-V2) between the valleys and the peaks with respect to the thickness of the epitaxial layer in the Example is small compared to the difference between the valleys and the peaks with respect to the thickness of the epitaxial layer in the comparative example (P1-V1). have.

The above detailed description should not be construed as restrictive in all respects and should be considered as illustrative. The scope of the embodiments should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the embodiments are included in the scope of the embodiments.

10: wafer
100: epitaxial reactor
110: reaction chamber
120: susceptor
130: dome assembly
131: window
132, 133: upper flange
140: lower flange
141: gas inlet
142: gas outlet
143: reaction space
145: injection passage
146: exhaust passage
150: main shaft
151: heat source
200: baseline
P1: lowest point
P21, P22: Peak
H1: first height
H2: second height
R: radius of curvature
PV: difference between valleys and peaks for the thickness of the epitaxial layer

Claims (10)

reaction chamber;
a susceptor installed inside the reaction chamber to support a wafer;
a window convex in a downward direction;
a first upper flange for fastening the window along the periphery of the window;
a second upper flange surrounding the first upper flange;
a lower flange engaged with the second upper flange under the second upper flange; and
Including; an injection passage formed between the second upper flange and the lower flange;
A reference line connecting the lowest points of each of the first and second sides of the first upper flange surrounding the window is defined, the lowest point of the window is defined at the center of the window, and the highest point of the window at the edge of the window is defined. the ratio of the second height to the first height when the distance between the reference line and the lowest point of the window is defined as a first height, and the distance between the reference line and the highest point of the window is defined as the second height. is 1.15 to 2.25,
The surface between the center of the window and the edge of the window has a surface of curvature.
epitaxial reactor. According to claim 1,
The difference between the valley and the peak for the thickness of the epitaxial layer grown on the wafer is 7.5 mm to 10 mm.
epitaxial reactor. ◈Claim 3 was abandoned when paying the registration fee.◈ According to claim 1,
The wafer has a diameter of 300 mm.
epitaxial reactor. According to claim 1,
The window has a radius of curvature of 8,200 mm to 10,300 mm.
epitaxial reactor. According to claim 1,
The first height is 4mm to 6mm
epitaxial reactor. According to claim 1,
The second height is 7mm to 9mm
epitaxial reactor. According to claim 1,
The radius of curvature of the window varies according to at least one of the first height and the second height.
epitaxial reactor. According to claim 1,
When the second height increases when the first height is fixed, the radius of curvature of the window becomes small.
epitaxial reactor. According to claim 1,
When the first height is reduced when the second height is fixed, the radius of curvature of the window becomes smaller.
epitaxial reactor. delete

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