Inline system for coating individual or groups of substrates and method for coating individual substrates or groups of substrates in an inline coating system

Description

[0001] The invention relates to an inline system for coating individual or groups of substrates, comprising several chambers arranged in series and evacuable by pumps, namely an inlet chamber, a waiting chamber, at least one process chamber, a further waiting chamber and an outlet chamber, which are passed through successively by the substrates or groups of substrates and which can each be closed by valves.

[0002] The invention further relates to a method for coating individual substrates or groups of substrates in such an inline coating system.

[0003] From WO 2011 / 121665 A1, a device for manufacturing an electronic component is known which uses an in-line system, wherein particles are prevented from flowing from a film formation chamber into a process chamber of the subsequent step. A buffer chamber is arranged between the film formation chamber and the process chamber of the subsequent step, with slide valves located between them, and the particles generated in the film formation chamber are removed from the buffer chamber by releasing air through independent opening / closing of the slide valves upstream and downstream of the buffer chamber.

[0004] DE 41 11 384 A1 discloses a method and a device for coating substrates, preferably by means of cathode sputtering in a vacuum system, comprising at least one sputtering chamber in which different coating systems can be applied to the preferably curved substrates to be coated, the substrates being movable through the vacuum system in one direction of movement and passing through the sputtering chamber multiple times in the direction of movement and in the opposite direction in so-called multipass mode, wherein the substrates to be coated are grouped into groups of several, preferably two, substrates or the carriers receiving the substrates before entering the sputtering chamber and these pass through the sputtering chamber simultaneously in so-called dual multipass mode.

[0005] EP 0 210 578 A2 discloses a system and a method for applying an electrical insulator to a substrate. The system comprises a first, a second, and a third chamber, the second chamber being a deposition chamber for applying the insulator to the substrate. A plurality of gas locks connects the second chamber to the first chamber and the second chamber to the third chamber in series. An endless conveyor in each of the chambers transports the substrate sequentially through the chambers. Several pumps for regulating the absolute pressure ensure a unidirectional gas flow from the first and third chambers into the second chamber to maintain a desired degree of insulation, which can be expressed as the concentration ratio of the gas components between the chambers.

[0006] Workpiece coatings are used, for example, to increase the wear resistance and service life of components. Tool coatings also frequently serve as corrosion protection or to improve physical properties. The processes discussed here are chemical vapor deposition (CVD) and physical vapor deposition (PVD), which has the advantage of a significantly lower deposition temperature compared to CVD. In addition to batch processes in so-called batch systems, where a large number of workpieces are stationary in a coating vessel during coating, coatings are also applied in a continuous process, in which the substrates pass through various stations sequentially in continuous flow systems.These stations are implemented using various chambers of an inline system. Within these chambers, the vacuum necessary for CVD or PVD processes is generated, and the workpiece surfaces are etched and coated, potentially with two layers applied sequentially. For very thin layers, such as optical coatings or coatings for batteries and fuel cells, the evacuation and ventilation time becomes the speed-determining step, defining the system's productivity. For example, surface etching and coating each require approximately one minute, whereas loading and unloading can potentially be performed by a robot in less than one minute. Due to technical limitations, such short loading and unloading processes are not feasible. The technically achievable limit for these processes appears to be around two minutes.

[0007] In Fig. 1A system consisting of five chambers, known according to the prior art, is outlined. It comprises a loading area, an inlet chamber, an etching chamber, two successive coating chambers, an outlet chamber, and an unloading area. Each of these chambers is equipped with pumps and connected by valves, allowing them to be selectively and independently vented and aerated.

[0008] In Fig. 1Five different loading states are sketched, designated by line numbers 1, 2, 3, 4, and 5. The workpieces bear the reference numbers 11, 12, 13, 14, and 15. The coating chambers are designed to accommodate one of the workpieces 11 to 15 at a time. Workpiece 15 is located in the loading area, while workpiece 14 is temporarily stored in the infeed chamber until the required vacuum pressure is reached. Simultaneously, workpiece 13 is etched in an etching chamber, and workpiece 12 receives a first coating in a first coating chamber, while workpiece 11 receives a second coating (as an outer layer on top of the first) in a second coating chamber.

[0009] Specifically, the evacuation and ventilation times of the system are each 2 minutes. In the second step (second line), after opening the corresponding valves, workpieces 11, 12, 13, and 14 are each moved into the next chamber: workpiece 14 into the etching chamber, workpiece 13 into the first coating chamber, workpiece 12 into the second coating chamber, and workpiece 11 into the discharge chamber. The end of this transfer is shown in the third line. Following this, the infeed chamber is opened to introduce workpiece 15, and simultaneously, workpiece 11 is moved out of the discharge chamber after ventilation, as shown in the fourth line.

[0010] Once workpiece 15 is positioned in the infeed chamber and workpiece 11 has been transported from the outfeed chamber to the unloading area, the valves of both the infeed and outfeed chambers are closed, after which the infeed chamber is evacuated. Simultaneously, the surface etching—the first coating and the second coating—of the respective workpieces located in the chambers is completed. The last line, also marked with the number "1," indicates the provision of another workpiece 16.

[0011] The above-described throughput process has a cycle time that is determined by the evacuation time of 2 minutes.

[0012] The object of the present invention is to improve an inline system of the type mentioned above or a method of the type mentioned above in such a way as to achieve higher productivity.

[0013] This problem is solved by an inline system according to claim 1 or by a method according to claim 5.

[0014] According to the invention, the inlet and outlet chambers are each enlarged to provide a throughput length sufficient for the simultaneous intake of n substrates or substrate groups arranged one after the other or side by side, where n is a natural number. The waiting chamber, located between the inlet and process chambers and between the outlet and process chambers, has a capacity to accommodate (n-1) substrates or substrate groups, whereas the capacity of each treatment chamber is limited to accommodating one substrate. The inlet and outlet chambers are preferably n times as long as the treatment chambers, namely the chambers of equal length for etching and coating, while the waiting chambers are n-1 times as long as the treatment chambers.This ensures that a vacuum necessary for the process is simultaneously created in the venting chamber for n substrates or substrate groups. The most time-consuming process of venting and purging is thus "distributed" across n substrates or n substrate groups, so that the most time-consuming steps of the two outer chambers (for purging and purging) only need to be performed every nth cycle, and the cycle time of the other chambers, which is significantly shorter, can be maintained. While enlarging the two outer chambers (namely the inlet and outlet chambers) and adding respective waiting chambers does increase the plant costs, this is offset by the n-fold increase in the plant's productivity. In any case, the additional plant costs are significantly lower than setting up multiple production lines to achieve the same cycle times.

[0015] Preferably, the inline system comprises an etching chamber as the first process chamber and at least one coating chamber, preferably two coating chambers, for the deposition of successive layers. According to a further embodiment of the invention, the coating chambers include a PVD unit.

[0016] The process is solved by moving and treating the substrates or substrate groups in combination between the respective etching and / or coating treatments from the inlet chamber via the waiting chamber into the treatment chamber and another waiting chamber into the outlet chamber in such a way that in successive steps the inlet chamber is occupied with n substrates or n substrate groups and each of the treatment chambers with only one substrate or substrate group, and the waiting chambers are free of substrates or substrate groups.In a subsequent step, the substrates or substrate groups are moved forward together, so that after completion of this step, a substrate or substrate group ejected from each treatment chamber is replaced by a substrate or substrate group being fed in, and that after partial occupancy of the waiting chamber, the loading chamber is loaded with n substrates or substrate groups, after which the previously described sequence of substrate movement and chamber loading is successively repeated.

[0017] The core idea of ​​the present invention is that the maximum occupancy rate of the entry and exit chambers is greater by an integer factor n.

[0018] Exemplary embodiments of the invention are described in Figs. 2 to 4 depicted.

[0019] In Fig. 2Line 1 shows that the inlet chamber E and the outlet chamber A are approximately twice as long as the other chambers, namely the two waiting chambers W1 and W2, and the centrally located treatment chambers B, in this case etching chamber B1, coating chamber B2, and coating chamber B3. Substrates 21, 22 and 26, 27 are located in the inlet and outlet chambers, respectively, while substrates 23, 24, and 25 are simultaneously located in the etching chamber, the first coating chamber, and the second coating chamber. The waiting chambers are empty. The valves between the individual chambers are closed, allowing the inlet chamber to be evacuated to the low pressure required for PVD treatment. The outlet chamber is already vented during the evacuation of the inlet chamber.Simultaneously, substrate 25 is treated in etching chamber B1, and substrates 23 and 24 are coated in coating chambers B2 and B3. After the time defined by the pumping process has elapsed, the valves between the inlet chamber E and the first waiting chamber W1, as well as from waiting chamber W1 to etching chamber B1 and from there to coating chambers B2 and B3, up to the second waiting chamber W2, are opened. The last valve in the outlet chamber A is then vented. The substrates 21, 22, 23, 24, 25, 26, 27 are each pushed into the adjacent chamber (in the image in line 2 to the right) two chambers further until the occupancy rate shown in the third line is reached, in which the inlet chamber E and the outlet chamber A are completely empty and there is one substrate in the etching chamber B 1 and the two coating chambers B2, B3.Substrates 23, 27 are arranged in the waiting chambers; the two finished substrates 21, 22 have been discharged simultaneously.

[0020] Line 4 illustrates how the inlet chamber E is loaded with two substrates 28, 29, while simultaneously substrate 27 is transferred to etching chamber B1 and substrates 25, 26 to chambers B2, B3 for the first and second coating, respectively. The substrate 23, previously located in the second waiting chamber W2, is simultaneously transferred to the discharge chamber A, thus restoring the initial situation in which inlet chamber E contains two substrates 28, 29, treatment chambers B1 to B3 each contain one substrate 25, 26, 27, and discharge chamber A contains two substrates 23, 24. The process then restarts. The valves shown, which are designed, for example, as slide valves, are only opened when a substrate is to be transferred from one chamber to the next. The end valves of the inlet chamber E and the outlet chamber A are only opened for ventilation. Fig. 2It is evident that two substrates or substrate groups are successively fed into the inlet chamber E, and two substrates are simultaneously removed from the outlet chamber A. The double occupancy of both the inlet chamber E and the outlet chamber A results in a reduced evacuation and aeration time per substrate, thus increasing the overall product yield.

[0021] Fig. 3 Figure 1 shows a sketched alternative embodiment of an inline system for the simultaneous intake of two adjacent substrates 32, 33 in the infeed chamber E and 37, 38 in the outfeed chamber A, respectively. At the beginning of the process shown in line 1, individual substrates 34 are located in the etching chamber B1, 35 in the coating chamber B2, and 36 in the coating chamber B3. In contrast to Fig. 2To illustrate the parallel arrangement, a top view of the system has been chosen. At the beginning of the process shown in line 1, the inlet chamber E is evacuated and the outlet chamber A is ventilated.

[0022] In the subsequent step, shown in the second line, all substrates 32 to 36 are transferred to the adjacent chamber, and new substrates 39 and 40 are simultaneously made available in the loading area. The final state after this transfer is shown in the third line, which also describes the ventilation of the inlet chamber E. At this point, substrate 32 is located in the waiting chamber W1, with the valve between the inlet chamber and the waiting chamber closed, as well as the valve between the waiting chamber and the etching chamber B1, where substrate 33 is located. Substrates 34 and 35 are coated in chambers B1 and B2, respectively. Substrate 36 remains in the waiting chamber W2 during this time, while the already processed substrates 37 and 38 have already been removed. The discharge chamber A is evacuated after the discharge process.All ventilation and evacuation procedures take approximately 1 minute.

[0023] After etching and coating, substrates 33, 34, and 35 are advanced to the next adjacent chamber, as shown in the fourth line. Upon completion of this process, substrates 39 and 40 are located in the infeed chamber, waiting chamber W1 is empty, and substrates 32, 33, and 34 are simultaneously treated in adjacent chambers B1, B2, and B3, respectively. At this time, waiting chambers W1 and W2 are emptied. All valves, except for the end valve of the discharge chamber, are closed. The discharge chamber, which again contains two adjacent substrates 35 and 36, is vented, after which the next process is started, as shown in the last line. In this chamber arrangement, both the infeed and discharge chambers are designed as magazines.

[0024] Another process and inline plant variant shows Fig. 4 In this embodiment, the inlet and outlet chambers are dimensioned to each accommodate three substrates simultaneously. In the illustrated example, the substrates are arranged one behind the other, but they can also be arranged side by side.

[0025] At the start of a process, substrates 43, 44, and 45 are located in an inlet chamber E, which is evacuated, for example, for 0.4 minutes. During the same time, waiting chambers W1 and W2 are empty, while substrate 46 is being processed simultaneously in etching chamber B1, substrate 47 in coating chamber B2, and substrate 48 in the second coating chamber B3. Three substrates 49, 50, and 51 are located in the discharge chamber and are discharged after the discharge chamber has been ventilated (see second line). Simultaneously with the discharge, the substrates are moved until the state shown in the third line is reached, in which two substrates 43 and 44 are being processed in the waiting chamber, and substrates 45, 46, and 47 are being processed in each of the treatment chambers B1, B2, and B3. Substrate 48 is located in the waiting chamber. The inlet chamber is being ventilated while the outlet chamber is still being evacuated.As shown in the fourth line, the inlet chamber can now be loaded with new substrates 52, 53, 54. The transfer of substrates 43, 44, 45, 46 into the adjacent chamber with the valves open is shown in line 4. After loading the inlet chamber E, this chamber (see fifth line) is evacuated, while substrate 43 is in the waiting chamber W1 and substrates 44, 45, 46 are in their respective treatment chambers B1, B2, B3, where they are etched or coated with the first or second layer, respectively. Substrates 47, 48 are in the waiting chamber W2. The discharge chamber is evacuated.After evacuation and treatment, substrates 43, 44, 45, 46, 47, and 48 are conveyed until an arrangement corresponding to the initial situation is reached, in which three substrates 52, 53, and 54 are evacuated in the inlet chamber, substrates 43, 44, and 45 are etched or coated in treatment chambers B1, B2, and B3, respectively, and substrates 46, 47, and 48 are arranged in the outlet chamber, which is already being ventilated. After a treatment and evacuation / ventilation time of 0.4 minutes, the process continues as shown in the last line.

[0026] Out of Figures 2 to 4 It becomes clear that the inlet and outlet chambers can each be loaded with n=2 or n=3 substrates, whereas the waiting chambers have a loading capacity of two substrates. Only one substrate can be placed in each of the treatment chambers.

[0027] The insertion of additional waiting chambers and the increase in capacity of the entry and exit chambers require comparatively less investment than the revenue that can be achieved through the increase in productivity.

Claims

1. In-line installation for coating individual substrates or groups of substrates (21, 22, 23, 24, 25, 26, 27), which has a plurality of chambers (E, W1, W2, B, B1, B2, 83, A) arranged one behind the other and evacuable by pumps, namely a load-lock chamber (E), a buffer chamber (W1), at least one process chamber (B, B1, B2, 83), a further buffer chamber (W2) and an unload-lock chamber (A), which are successively traversed by the substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups and which can each be closed by valves, characterized in that the load-lock and the unload-lock chamber (E, A) in each case have a capacity for the simultaneous accommodation of n substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups arranged one behind the other or next to one another, n being a natural number Z greater than 1, and that the buffer chamber (W1, W2) arranged between the load-lock chamber (E) and the process chamber (B, B1, B2, 83) and between the unload-lock chamber (A) and the process chamber (B, B1, B2, 83) has a capacity for receiving (n-1) substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups, whereas the capacity of the treatment chambers (B, B1, B2, 83) is in each case restricted to receiving one substrate (21, 22, 23, 24, 25, 26, 27) or one substrate group.

2. In-line installation according to claim 1, characterized in that the load-lock and the unload-lock chamber (E, A) are n times as long as each of the treatment chambers (B, B1, B2, 83).

3. In-line installation according to claim 1 or 2, characterized in that as process chambers (B, B1, B2, 83) an etching chamber (B1) and one, preferably two coating chambers (B2, 83) are provided.

4. In-line installation according to any one of claims 1 to 3, characterized in that the coating chambers (B2, 83) have a PVD apparatus.

5. Method for coating individual substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups in an in-line coating installation according to any one of claims 1 to 4, characterized in that between the respective etching and / or coating treatments the substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups are moved and treated as a unit from the load-lock chamber (E) via the buffer chamber (W1) into the treatment chambers (B, B1, B2, 83) and a further buffer chamber (W2) into the unload-lock chamber (A) in such a way that in successive steps the load-lock chamber (E) is occupied with n substrates (21, 22, 23, 24, 25, 26, 27) or n substrate groups and each of the treatment chambers (B, B1, B2, 83) is occupied with in each case only one substrate (21, 22, 23, 24, 25, 26, 27) or one substrate group and the buffer chambers (W1, W2) are free of substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups, then the substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups are moved forward to such an extent that a substrate (21, 22, 23, 24, 25, 26, 27) or a substrate group discharged from each treatment chamber (B, B1, B2, 83) is replaced by a following substrate (21, 22, 23, 24, 25, 26, 27) or a following substrate group and that, after partial occupancy of the buffer chamber (W1, W2), the occupancy of the load-lock chamber (E) with n substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups is carried out, after which the sequence of substrate movement and chamber occupancy described above is repeated successively.

6. Method according to claim 5, characterized in that the substrates (21, 22, 23, 24, 25, 26, 27) or substrate groups are subjected to an etching process prior to coating.

7. Method according to claim 5 or 6, characterized in that the substrates (21, 22, 23, 24, 25, 26, 27) are coated in two layers.