KR200216948Y1 - Chemical Vapor Deposition Equipment - Google Patents

Abstract

The present invention discloses a chemical vapor deposition apparatus. In the disclosed subject matter, the placing plate 30 is disposed on the bottom surface of the deposition chamber 20, and the susceptor 36 on which the wafer W is placed is placed on the surface of the placing plate 30. On the bottom surface of the susceptor 36, a heating wire 35 for applying heat to the wafer W is disposed. A cover 21 is installed at an upper portion of the deposition chamber 20, and a gas mixer 40 is installed at the bottom of the cover 21. The cover 21 is connected to several inlet lines 51, 52, and 53 to which several reaction gases are introduced independently, and a high frequency application line 50 for applying a high frequency power source to plasma the mixed reaction gases. It is connected to the cover 21. Several reactant gases are supplied independently to the spray head 70 provided at the bottom of the gas mixer 40, and each reactant gas is sprayed from the spray head 70 to be plasmalized in the deposition chamber 20 and then wafer (W) Sprayed to the surface. Several independent gas supply passages 54, 55, 56 are provided from each inlet passage 51, 52, 53 to the injection head 70 via the gas mixer 40, so that the reaction gases are premixed in the gas mixer. Will not be. In addition, an uneven groove 41 is formed in the outer wall of the gas mixer 40, and the time for which the plasma gas is deposited on the outer wall of the gas mixer 40 is delayed.

Description

Chemical Vapor Deposition Equipment

The present invention relates to a chemical vapor deposition apparatus (CVD), and more particularly to a device for depositing a barrier metal layer interposed between a semiconductor substrate and a metal film to prevent electromigration (electromigration). .

In general, a barrier metal film is deposited to prevent electromigration before the metal wiring film is formed in a predetermined pattern on the semiconductor substrate. Electromigration refers to a phenomenon in which electrons are transferred or stress propagates between a substrate and a metal wiring film. When the electromigration phenomenon occurs, both the substrate and the metal wiring film are damaged, so that the barrier metal film is first deposited on the substrate, and then the metal wiring film is formed on the barrier metal film, thereby preventing the movement of electrons or the stress propagation. . As the barrier metal film, a titanium / titanium nitride film (Ti / TiN) is usually used.

The barrier metal film having the above function is deposited by chemical vapor deposition, and the chemical vapor deposition apparatus for this purpose is shown in cross section in FIG.

As shown, the cover 2 is provided on the upper part of the deposition chamber 1 via the O-ring 3. A bowl-shaped settling plate 4 is disposed on the bottom of the deposition chamber 1, and a susceptor 9 on which the wafer W is placed is provided on the surface of the settling plate 4. At the lower part of the susceptor 9, a hot plate 11 for applying heat to the wafer W is disposed. On the other hand, an entrance and exit through which the wafer W enters and exits is formed on the side of the deposition chamber 1, and the entrance and exit is opened and closed by the slit door 10.

The wafer W brought into the deposition chamber 1 through the entrance and exit is placed on top of three lift pins 7 above the susceptor 9, each lift pin 7 being shown in FIGS. 3 and 4. As described above, they are arranged at equal intervals of 120 degrees and are integrally connected by three bridges 6. The center of each bridge 6 is connected to the lifting shaft 5 which moves up and down along the interior of the settling board 4.

The side of the cover 2 is connected with three reaction gas inlet tubes 12 into which titanium chloride (TiCl ₄ ) gas, which is a main reaction gas, and two other gases, are injected, and a high frequency power source (Ph) A high frequency application line 13 for applying RF power to the deposition chamber 1 is connected to the top of the cover 2. At the bottom of the cover 2, a gas mixer 14 into which each reaction gas is mixed is provided. Inside the gas mixer 14, three diffusion rings 15 are provided which provide a passage for moving each reaction gas. On the other hand, the injection head 16 which injects the mixed reaction gas to the surface of the wafer W is provided in the bottom surface of the gas mixer 14. Since the reaction gases are injected from the injection head 16 and plasmated inside the deposition chamber 1, as shown in FIG. 2, a high frequency application line 13 is continued to the injection head 16.

On the other hand, the vacuum chamber 18 is connected to the deposition chamber 1, and the vacuum pump 19 is provided in the vacuum line 18. Further, a baffle plate 17 is provided on the inner wall of the deposition chamber 1 for controlling the vacuum pressure provided through the vacuum line 18.

As configured above, three reaction gases are introduced through the inlet tube 12 to pass between the three diffusion rings 15 and then mixed inside the gas mixer 14. The mixed gases are jetted into the deposition chamber 1 by the injection head 16 and then plasmalized, and then sprayed onto the surface of the wafer W heated by the hot plate 11, thereby forming a barrier metal on the wafer W surface. The film is deposited.

However, the conventional chemical vapor deposition apparatus has the following problems.

First, conventionally, three process gases are premixed inside the gas mixer 14. Due to this, process gases are prematurely reacted and deposited on the inner wall of the gas mixer 14 and the spray head 16, and are very likely to act as fine particles in the actual deposition process.

Secondly, as the deposition process proceeds, a film is deposited not only on the surface of the wafer W but also on the outer wall of the gas mixer 14, which short-circuits between the gas mixer 14 and the bottom of the cover 2, and also fines. Will also work. By the way, since the outer wall of the conventional gas mixer 14 is a flat structure, there exists a problem that deposition rate is very fast. In particular, the conventional gas mixer 14 has a problem of alumina in which deposition occurs very easily.

Thirdly, since the conventional lifting pins 7 are three-in-one structure by the bridge 6, the contact area between the wafer W and the lifting pins 7 is large, so that the conductivity becomes too high. That is, since a large part of the heat transferred from the hot plate 11 to the wafer W is released from the lifting pins 7 and the bridge 6, the uniformity of heat transferred to the wafer W is lowered, resulting in the deposition of the deposited film. Uniformity is lowered. And since there is much contact area, there is also a possibility that the back surface of the wafer W will generate | occur | produce a scratch.

Fourth, the material of the conventional susceptor 9 is nickel, which is very susceptible to damage by NF ₃ gas, which is a mixed gas, and the nickel-silicide formation reaction during the initial deposition process. ) Is a problem that the phenomenon that the pressing on the surface of the susceptor (9) made of nickel material occurs.

The present invention was devised to solve all the problems of the conventional chemical vapor deposition apparatus as described above, so that the three reaction gases are not reacted prematurely in the gas mixer, and the film is deposited on the inner wall of the gas mixer and the injection head. It is an object of the present invention to provide a chemical vapor deposition apparatus that can prevent the action of the fine particles.

Another object is to delay the rate at which the film is deposited on the outer wall of the gas mixer, thereby preventing the gas mixer and the cover from being shorted.

Another object is to reduce the contact area between the lift pins and the wafer to improve the uniformity of heat applied to the wafer.

In particular, another object is to change the material of the susceptor so as to prevent the susceptor from being damaged by the mixed gas or the wafer being pressed against the susceptor.

1 is a front sectional view showing a conventional chemical vapor deposition apparatus

Figure 2 is a partially enlarged cross-sectional view showing a conventional chamber upper structure

3 and 4 are a plan view and a front view showing a conventional lifting pin arrangement structure

Figure 5 is a front sectional view showing a chemical vapor deposition apparatus according to the present invention

Figure 6 is a partially enlarged cross-sectional view showing the upper structure of the chamber which is the main part of the present invention

7 and 8 are a plan view and a front view showing a lifting pin which is a main part of the present invention

-Explanation of symbols for the main parts of the drawing-

20; Deposition chamber 21; cover

30; Arthropod 31; Lifting pin

32; Lifting shaft 33; bridge

35; Hot plate 36; Susceptor

40; Gas mixer 41; Uneven groove

50; High frequency applied lines 51,52,53; Reaction Gas Inlet Tube

54,55,56; Gas supply passage 60; Diffusion Ring

70; Spray head

Chemical vapor deposition apparatus according to the present invention to achieve the above object consists of the following configuration.

The base plate is disposed on the bottom of the deposition chamber, and the susceptor on which the wafer is placed is placed on the surface of the base plate. At the bottom of the susceptor is arranged a heating wire for applying heat to the wafer. A cover is installed at the top of the deposition chamber, and a gas mixer is installed at the bottom of the cover. Therefore, several inlet lines through which several reactant gases are introduced are connected to the cover, and a high frequency application line for applying a high frequency power source for plasmaizing the mixed reactant gases is connected to the cover. Several reactant gases are supplied independently to a spray head installed at the bottom of the gas mixer, which are injected into the deposition chamber by the spray head and then plasmalized inside the deposition chamber, which plasma gas is sprayed from the spray head to the wafer surface. It is done.

Here, the reactant gases are mixed in the injection head rather than inside the gas mixer. To this end, several independent gas supply passages are provided from each inlet passage through the gas mixer to the injection head. In addition, in order to delay the time that the plasma gas is deposited on the outer wall of the gas mixer, an uneven groove is formed in the outer wall of the gas mixer to expand the deposition area. In addition, the material of the gas mixer is preferably quartz that is not well deposited.

In addition, the wafer brought into the deposition chamber is placed on three lift pins, and each lift pin is connected to a lift shaft that is lifted along the axis of the base plate. At this time, the bridge connecting the lifting shaft and each lifting pin is disposed inside the base plate, so that the contact area between the lifting pin and the wafer is minimized. In addition, in order to prevent damage by the mixed plasma gas, it is also preferable to apply an aluminum coating to the susceptor.

According to the above-described configuration of the present invention, several reaction gases are not mixed inside the gas mixer but mixed inside the injection head through an independent gas passage, so that the reaction gas reacts to the inner wall of the gas mixer and the injection head by premature reaction. The film is prevented from depositing. Further, as the uneven groove is formed in the outer wall of the gas mixer and the area is expanded, the rate at which the film is deposited on the entire outer wall of the gas mixer is delayed. The wafer is supported by three independent lift pins, thereby minimizing the contact area between the wafer and the lift pins.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 5 is a front sectional view showing a chemical vapor deposition apparatus according to the present invention, Figure 6 is a partial enlarged cross-sectional view showing the upper structure of the chamber which is the main part of the present invention, Figures 7 and 8 are lifting pins that are the main part of the present invention Top and front views shown.

As shown in FIG. 5, a cover 21 is installed at an upper portion of the deposition chamber 20 via an O-ring 22. A bowl-shaped set plate 30 is disposed on the bottom of the deposition chamber 20. On the other hand, although not shown, the wafer W is carried in through a doorway formed at the side of the deposition chamber 20, and a vacuum line and a vacuum pump for providing a vacuum to the deposition chamber 20 are also provided.

An empty gas mixer 40 is installed on the bottom surface of the cover 21. An injection head 70 for injecting plasma gas onto the wafer W surface is installed at the bottom of the gas mixer 40. Inlet tubes 51, 52, and 53 into which three reaction gases are introduced are connected to the cover 21, and each of the inlet tubes 51, 52, and 53 has three diffusion rings (as shown in FIG. 6). It leads to the injection head 70 through a separate gas passage provided by 60. That is, according to the present invention, each reaction gas is mixed in the injection head 70 without prematurely mixing in the gas mixer 40. In this way, a high frequency application line 50 for plasmalizing the reaction gas mixed in the injection head 70 is connected to the center of the upper surface of the cover 21, and the lower end thereof is injected through the gas mixer 40. Leads to).

Again, in FIG. 5, the plasma gas is also deposited on the wafer W surface but also on the outer wall of the gas mixer 40. When the film deposited on the outer wall of the gas mixer 40 is connected to the bottom surface of the cover 21, the gas chamber 40 and the cover 21 are short-circuited, and thus the deposition chamber 20 should be periodically cleaned. However, the more frequent the cleaning cycle is to reduce the operating time of the equipment, it is necessary to delay the time the film is deposited on the outer wall of the gas mixer 40 in order to increase the cleaning cycle. To this end, in the present invention by forming the groove 41 of the concave-convex shape on the outer wall of the gas mixer 40, the outer wall area of the gas mixer 40 is expanded. In addition, in order to prevent deposition, the material of the gas mixer 40 is changed from conventional alumina to quartz. Thus, the time taken for the film to be deposited over the entire outer wall of the expanded gas mixer 40 is extended.

On the other hand, as shown in FIGS. 7 and 8, the wafer W is placed on the surface of the susceptor 36 provided on the surface of the placement plate 30. On the bottom of the susceptor 36 is arranged a heating wire 35 for applying heat to the wafer W, which is composed of several concentric circles. In addition, a cooling line 34 for cooling the susceptor 36 is also provided.

The wafer W carried into the deposition chamber 20 is supported by three lifting pins 31 arranged at equal intervals of 120 ° above the susceptor 36, and then the lifting pins 31 are lowered so that the wafer W is lowered. It is placed on the surface of the acceptor 36. Therefore, each lifting pin 31 is connected by the bridge 33 to the lifting shaft 32 which is elevated along the axis of the base plate 30, which bridge 33 is conventionally the upper portion of the base plate 30. Although disposed on the outside, in the present invention, it is disposed inside the base plate 30 while being the lower portion of the hot plate 35. This is to minimize the contact area between the wafer W and the lift pins 31. In addition, in order to prevent the susceptor 36 from being damaged by NF ₃ , which is one of the components of the plasma gas, it is preferable to coat the susceptor 36 with aluminum.

Hereinafter, the operation of this embodiment configured as described above will be described in detail.

The deposition chamber 20 is provided with a vacuum pressure through a vacuum line, and is maintained in a vacuum state. In this state, the wafer W is carried by the robot arm through the entrance and into the deposition chamber 20, and then supported by three lifting pins 31 which are raised, and the robot arm moves out of the deposition chamber 20. do. As the lifting shaft 32 is lowered, the lifting pin 31 is also lowered, so that the wafer W is placed on the susceptor 36 surface. The wafer W is heated to the deposition temperature condition by the hot plate 35.

During this operation, heat transferred from the hot plate 35 to the wafer W is uniformly transferred to the wafer W. In particular, heat transfer is facilitated in the center of the wafer W where heat radiation is severely generated in the conventional apparatus. The reason for this is because the bridge 33 positioned below the center of the wafer W and connecting the three lifting pins 31 is located inside the placement plate 30 instead of outside the placement plate 30. This is because the heat dissipation through 33) is reduced.

In this state, reaction gases are introduced through the respective inlet tubes 51, 52, and 53. Each reaction gas is supplied to the injection head 70 through three independent supply passages 54, 55, 56 provided by the diffusion rings 60. That is, the respective reaction gases are not mixed in advance in the gas mixer 40, but are mixed in the injection head 70. Thus, the reaction gases are premixed in the gas mixer 40 to cause premature reaction, thereby preventing the film from being deposited on the inner walls of the gas mixer 40 and the injection head 70.

Each reaction gas supplied to the injection head 70 is injected into the deposition chamber 20, and is then generated as plasma gas by a high frequency power source provided from the high frequency application line 50. The plasma gas is injected from the spray head 70 to the wafer W surface, whereby a barrier metal film is deposited on the wafer W surface.

At this time, the plasma gas is deposited on the outer wall of the gas mixer 40 as well as the surface of the wafer (W) through a number of processes, the uneven groove 41 is formed on the outer wall of the gas mixer 40 to expand the area Therefore, the time that the film is deposited on the entire outer wall of the gas mixer 40 is delayed. In addition, since the material of the gas mixer 40 is quartz, which is not well deposited, the deposition time is further delayed.

On the other hand, the susceptor 36 may be damaged by the plasma gas injected into the surface of the wafer W, in particular, NF ₃ gas, and the wafer W may stick to the surface of the susceptor 36. Since the aluminum coating film is formed in 36), less damage is caused and the sticking phenomenon of the wafer W is prevented.

As described above, according to the present invention, the respective reaction gases are not premixed in the gas mixer but are supplied to the injection head through an independent gas passage, thereby preventing the film from being deposited on the inner wall of the gas mixer and the injection head by the early reaction. . Thus, the film is prevented from acting as a fine particle having a fatal adverse effect during the actual deposition process.

In addition, since the material of the gas mixer is changed from conventional alumina to quartz and the uneven groove is formed on the outer wall thereof, the time for the plasma gas to be deposited on the entire outer wall of the gas mixer is delayed. Therefore, the film deposited on the outer wall of the gas mixer is prevented from shorting between the gas mixer and the cover, and also prevented from later acting as fine particles.

Then, as the bridge connecting the lifting pins is moved into the base plate, the heat applied to the wafer is suppressed from being released through the bridge. Therefore, uniform heat can be transferred to the entire wafer, thereby improving the uniformity of the deposited film.

In addition, since the aluminum film is coated on the susceptor, damage to the susceptor due to plasma gas and the phenomenon that the wafer is pressed against the susceptor are prevented.

On the other hand, the present invention is not limited to the above-described specific preferred embodiment, any person having ordinary knowledge in the field to which the present invention belongs without departing from the gist of the present invention claimed in the claims can be variously modified. will be.

Claims (4)

An evaporation chamber in which an entrance through which a wafer is loaded / exported is formed at a side, and a vacuum line is connected; A cover installed at an upper portion of the deposition chamber and connected to an inflow line of reaction gases and a high frequency application line for applying a high frequency power supply to plasma the reaction gases; An arthropod installed at the bottom of the deposition chamber; A lifting shaft which is lifted along an axis of the base plate; A lifting pin connected to the lifting shaft at an equal interval to 120 ° and lifting up and down while supporting the wafer; A susceptor disposed on the surface of the settling plate and having a wafer lowered by the lifting pins; A hot plate disposed on a bottom surface of the susceptor to apply heat to the wafer; A gas mixer installed at the bottom of the cover; A plurality of diffusion rings disposed inside the gas mixer to form a supply passage of the respective reactive gases; And a spray head installed at a bottom surface of the gas mixer, to which the high frequency application line is connected, and spraying each of the reaction gases onto a wafer surface. Each of the inlet tubes and the injection head are directly connected by separate gas supply passages provided between the respective diffusion rings so that respective reaction gases are not premixed inside the gas mixer, The outer wall of the gas mixer, the chemical vapor deposition apparatus characterized in that the uneven groove is formed so that the outer wall area is extended so that the time that the plasma gas injected from the injection head is deposited on the entire outer wall is delayed. The chemical vapor deposition apparatus according to claim 1, wherein the gas mixer is made of quartz. The chemical vapor deposition apparatus according to claim 1, wherein the bridge connecting the lifting pins is disposed under the hot plate, which is inside the base plate, to prevent the release of heat transferred from the hot plate to the wafer. The chemical vapor deposition apparatus according to claim 1, wherein the susceptor is coated with an aluminum film for preventing damage caused by plasma gas and sticking of the wafer.