JP2868767B2 - Semiconductor wafer processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor wafer
The present invention relates to a semiconductor wafer processing apparatus that performs processing such as plasma CVD or etching using R (electron cyclotron resonance) plasma. [Prior Art] As an example of the semiconductor wafer processing apparatus described above, FIG. 3 shows a conventional configuration of a plasma CVD apparatus using a single-wafer processing method. In the figure, reference numeral 1 denotes a process reaction chamber made of a stainless steel material, 2 denotes a plasma generation chamber in which a magnetron 4 as a microwave oscillator is connected via a waveguide 3 and an excitation coil 5 is arranged around the chamber. A chamber 6; a load lock chamber adjacent to the process reaction chamber 1 via a vacuum gate valve 7; 8, a vacuum gate valve for partitioning a passage between the load lock chamber 6 and the outside atmosphere side; A vacuum exhaust system connected to the reaction chamber 1 and the load lock chamber 6, a wafer holding mechanism 11 equipped with an electrostatic chuck 12 installed in the process reaction chamber 1 facing the plasma generation chamber 2, and 13 a plurality of wafers This is a cassette in which semiconductor wafers 14 are housed side by side. With such a configuration, the process reaction chamber 1 and the plasma generation chamber 2 are evacuated to a vacuum, and a micro-oscillator oscillated by the magnetron 4 in a state where a carrier gas as a raw material for plasma generation is supplied to the plasma generation chamber 2 from the outside. Waves on waveguide 3
The ECR plasma is generated in the plasma generation chamber by applying a magnetic field by feeding through the excitation coil and energizing the excitation coil. On the other hand, the wafer is sent one by one into the process reaction chamber by the following transfer operation, and is transferred to and held by the wafer holding mechanism 11. That is, first, with the vacuum gate valves 7 and 8 closed and opened, respectively, the cassette 13 containing the unprocessed wafer is fed into the load lock chamber 6 from the outside by a cassette transfer means (not shown), and the vacuum gate valve 8 is closed. After that, the room is evacuated. Here, when the pressure of the load lock chamber 6 reaches a vacuum pressure equivalent to that of the process reaction chamber 1, the vacuum gate valve 7 is opened, and the cassette is operated by operating a wafer handling mechanism (not shown) installed in the chamber. A single wafer 14 is taken out from 13, carried into the process reaction chamber, delivered to the wafer holding mechanism 11 in the chamber, and the vacuum gate valve 7 is closed again. In this state, when an ECR plasma is generated as described above while feeding a film forming material gas such as silane gas into the process reaction chamber 1, this plasma is extruded into the process reaction chamber to activate the silane gas, thereby generating the silane gas. By the action of the active species, various silicon-based thin films are formed on the surface of the wafer 14 depending on the type of the carrier gas. On the other hand, when the predetermined wafer processing is completed, the wafers 14 are loaded from the cassette 13
Then, the processing operation for the next wafer is performed. When all the wafers 14 stored in the cassette 13 have been processed, the vacuum gate valve 8 in the load lock chamber 6 is returned again.
Then, the cassette 13 is unloaded outside the room, the next cassette is loaded instead, and wafer processing is performed by the same operation as described above. [Problems to be Solved by the Invention] In the conventional apparatus described above, the load lock chamber 6 as a preparation chamber is provided between the process reaction chamber 1 and the outside atmosphere side.
Although the load lock chamber 6 is provided, the load lock chamber 6 is opened from the outdoor atmosphere side to open the vacuum gate valve 8 between the atmosphere side and the atmosphere once each time the cassette 13 is loaded and unloaded. Dust floating in the air enters and pollutes the room. In addition, dust that has entered the room adheres to the cassette, the handling mechanism, and the like, and dust that has re-scattered from the sliding portion of the handling mechanism during the subsequent transfer and transfer operations of the wafer with the process reaction chamber 1 causes a process reaction. It comes into the room 1. In addition, in the above-described wafer processing method such as plasma CVD, foreign matter such as dust that has entered the plasma reaction chamber has a great effect on the process processing, thereby deteriorating the film quality of the film formed by the process processing and improving the wafer quality and yield. make worse. Therefore, such a problem of dust contamination is an important and essential problem to be solved as a process processing apparatus in a practical mass production scale production line. As another problem, in an apparatus of a practical mass production scale, it is important to improve the productivity by reducing the time loss in the wafer loading and unloading steps as much as possible to increase the throughput. In this regard, in the conventional apparatus described above, since a series of steps including loading and unloading of the cassette 13 into and from the load lock chamber 6 are performed in series as a wafer transfer step, at least ten and several seconds are required as idle time. It is technically difficult to increase the throughput because it is spent. The present invention has been made in view of the above points,
The objective is to improve the wafer processing performance by significantly improving the wafer transfer path between the process reaction chamber and the outside atmosphere, thereby greatly reducing the contamination due to foreign matter such as dust entering from the outside. Another object of the present invention is to provide a semiconductor wafer processing apparatus which can sufficiently cope with practical mass production capable of increasing the throughput. [Means for Solving the Problems] To achieve the above object, according to the present invention, wafers are taken out one by one from a cassette containing semiconductor wafers and loaded into a process reaction chamber held at a vacuum pressure. And
Here, a single wafer processing type semiconductor wafer processing apparatus for performing a predetermined wafer processing and then carrying out the wafer from the process reaction chamber and storing it in a cassette, comprising a wafer holding mechanism for holding the wafer at a predetermined position in the chamber. First and second units equipped with a process reaction chamber equipped with a wafer processing means and vacuum evacuation systems installed in series with the process reaction chamber.
Between the lock chamber and the process reaction chamber and the first lock chamber,
A vacuum gate valve for individually partitioning each passage between the first lock chamber and the second lock chamber and between the second lock chamber and the outdoor atmosphere side; and a second valve for taking out a wafer from a cassette disposed outside the chamber. A handling mechanism provided outside the chamber for loading a wafer into the lock chamber, a relay delivery mechanism provided inside the second lock chamber to receive and hold one wafer loaded from the outside, and a relay mechanism provided inside the first lock chamber. And a handling mechanism for transferring a wafer between the relay transfer mechanism on the side of the second lock chamber and the wafer holding mechanism in the process reaction chamber. The lock chamber is evacuated every time a wafer is loaded. [Operation] Loading and unloading of wafers by the above configuration are performed as follows. First, with the air-side gate valve of the second lock chamber opened, a wafer destined for one wafer is taken out of the cassette by a handling mechanism disposed outside and sent to a relay transfer mechanism provided in the second lock chamber. Next, after closing the gate valve and evacuating the second lock chamber, the gate valve between the first lock chamber and the second lock chamber, which is always maintained at the vacuum pressure, is opened, and the equipment in the first lock chamber is installed. The wafer is taken into the first lock chamber by the handling mechanism and the gate valve between the wafer and the second lock chamber is closed. Next, the gate valve between the first lock chamber and the process reaction chamber is opened, the wafer waiting in the first lock chamber is carried into the process reaction chamber, and then transferred to the wafer holding mechanism installed in the chamber. Here, after returning the handling mechanism to the first lock chamber and closing the gate valve again, predetermined wafer processing is performed in the process reaction chamber. When the wafer processing is completed, the processed wafer is unloaded from the process reaction chamber via the first lock chamber and the second lock chamber in the reverse order of the above-described loading operation, and stored in a cassette waiting outside the chamber. Thus, a series of processes for each sheet is completed. Moreover, in the above-described wafer transfer step, the first lock chamber is always kept at a vacuum and is not opened to the atmosphere side, and communication with the second lock chamber is performed only when the chamber is evacuated. As a result, there is almost no intrusion of dust from the outside, and the room is maintained in a highly clean state. As a result, even when a wafer is transferred to and from the process reaction chamber, foreign matter such as dust is hardly introduced from the outside into the process reaction chamber, and thus the wafer processing performance can be greatly improved. In addition, in the wafer transfer process, the loading and unloading processes of the cassette in the lock chamber, which cause a loss time, become unnecessary, and two relay transfer mechanisms in the second lock chamber are provided for loading and unloading the wafer. Alternatively, two sets of equipment for loading and unloading wafers are independently connected to and installed in the process reaction chamber as a set of equipment including the first and second lock chambers and their accessories. This makes it possible to carry out the wafer loading and unloading steps in parallel, thereby greatly reducing the time required for a series of wafer transporting steps and improving the throughput as compared with the conventional apparatus. Note that a handling mechanism, a cassette, and the like, which are arranged on the outside air side facing the second lock chamber, are placed in a clean work space such as a clean bench. Furthermore, in the conventional apparatus, the process reaction chamber is made of stainless steel in terms of economy, workability, and the like. However, when stainless steel is subjected to plasma irradiation, impurities jump out from the surface of the steel material and are implanted into the wafer to improve processing characteristics. The problem of heavy metal contamination which causes a decrease is a problem. However, such a problem can be solved by configuring the process reaction chamber and the plasma generation chamber with pure aluminum in advance. [Embodiment] FIGS. 1 and 2 show different embodiments of the present invention, and the same members corresponding to FIG. 3 are denoted by the same reference numerals. First, in FIG. 1, on the side of the process reaction chamber 1, a first lock chamber 15 and a second lock chamber 16 are provided in series. Each lock chamber is individually equipped with vacuum evacuation systems 17 and 18, and between the process reaction chamber 1 and the first lock chamber 15,
Vacuum gate valves 19, 20, and 21 are provided between the first lock chamber 15 and the second lock chamber 16 and between the second lock chamber 16 and the outdoor atmosphere side to individually partition respective passages. Further, the second lock chamber 16 is provided with a relay transfer mechanism 22 for temporarily receiving and holding a wafer carried in from outside. The relay transfer mechanism 22 is configured to vertically move the wafer holder by a driving unit outside the room. On the other hand, the first lock chamber 15 is equipped with a handling mechanism 23 for transferring and transferring wafers between the wafer holding mechanism 11 in the process reaction chamber 1 and the relay transfer mechanism 22 in the second lock chamber. Have been. The handling mechanism 23 is a frog arm type mechanical pantograph type robot which has been conventionally used, and the wafer holder attached to the tip thereof is moved horizontally and vertically by an outdoor driving unit. The second lock chamber 16
A handling mechanism 24 is provided on the outside air side so as to transfer and deliver the wafer 14 between the cassette 13 and the relay delivery mechanism 22 in the second lock chamber.
The handling mechanism 24 is configured to take out one wafer contained in the cassette 13 with the processing surface facing upward, and then turn over the wafer and deliver it to the relay delivery mechanism 22 in the second lock chamber. This is a so-called face-down transfer type robot. The handling mechanism 24 is a clean bench 25 for cleaning the surrounding work space.
And so on. Each of the relay transfer mechanism 22 and the handling mechanisms 23 and 24 has a wafer holder for supporting the outer peripheral margin of the wafer 14 and protecting the processing surface. Next, a description will be made of the transfer and processing operations of the wafer with the above configuration in order. First, the process reaction chamber 1 and the first
The lock chamber 15 is always maintained at a predetermined vacuum pressure by the vacuum evacuation systems 9 and 17. Here, the cassette 13 containing the unprocessed wafer is set at a predetermined position in the clean bench 25, and the cassette 13 is operated by operating the handling mechanism 24 with the vacuum gate valve 21 opened and the second lock chamber 16 opened to the atmosphere. One more wafer 14 is taken out, and the wafer is turned upside down, and the processing surface is directed downward so that dust in the air is prevented from adhering to the processing surface as much as possible, and the wafer 14 is relayed in the second lock chamber. It is delivered to the delivery mechanism 22 and received and held here. When the second lock chamber 16 is opened to the atmosphere side, the vacuum gate valve 21 is gradually opened to allow a slow leak, and clean air is sent into the room to make the room pressure slightly higher than the atmospheric pressure. Care should be taken to prevent dust from entering from the side as much as possible. On the other hand, after transferring the wafer 14 to the relay transfer mechanism 22, the handling mechanism 24 is retracted, the vacuum gate valve 21 is closed, and the second lock chamber 16 is further evacuated. When performing the vacuum evacuation, a slow start is performed so that the dust that has invaded and accumulated from the atmosphere side will not be scattered again. Subsequently, when the pressure in the second lock chamber 16 drops to a predetermined vacuum pressure, the vacuum gate valve 20 between the second lock chamber 16 and the first lock chamber 15 is opened, and the wafer held by the relay transfer mechanism 22 is operated by operating the handling mechanism 23. 14 is taken into the first lock chamber 15. In this process, there is no pressure difference between the first lock chamber 15 and the second lock chamber 16, and the second lock chamber 16 is in a state where the floating dust is removed outside by the exhaust air. There is very little dust entering the 15. When the transfer of the wafer 14 is completed, the vacuum gate valve 20 is closed again. Next, the vacuum gate valve 19 between the process reaction chamber 1 and the first lock chamber 15 is opened, and the wafer holding mechanism 11 installed in the process reaction chamber while the wafer 14 is kept in the processing surface downward position by operating the handling mechanism 23. Hand over to Note that the wafer holding mechanism
Numeral 11 denotes a vacuum bellows 26 at a portion penetrating the process reaction chamber 1.
The position of the wafer holding mechanism 11 can be adjusted and adjusted to the optimum process conditions. On the other hand, when the transfer of the wafer 14 is completed, the handling mechanism 23 returns to the first lock chamber, and closes the vacuum gate valve 19 again. Now, when the unprocessed wafer 14 is held by the wafer holding mechanism 11, a predetermined process such as plasma CVD or etching is performed. The plasma processing operation is as described above. Here, when the processing of the wafer is completed, the processed wafer waits outside the process reaction chamber 1 via the first lock chamber 15 and the second lock chamber 16 in the reverse order of the above-described wafer loading operation. It is stored in the cassette 13. Thus, a series of steps for one wafer is completed, and then the next wafer is loaded into the process reaction chamber by the same operation as described above to perform predetermined processing. Next, FIG. 2 shows another embodiment. That is, in the embodiment of FIG. 1, the loading and unloading of wafers are performed alternately through the first and second lock chambers, whereas in the embodiment of FIG. And 16, a set of equipment including the lock chamber accessories and the outdoor handling mechanism 24, and two sets of equipment for loading and unloading wafers are installed independently on both sides of the process reaction chamber 1. Have been. With this configuration, the unloading operation of the unprocessed wafer and the unloading operation of the processed wafer can be performed in parallel on different transport paths, and therefore, the idle time can be significantly reduced as compared with the embodiment of FIG. Throughput can be improved. In the embodiment shown in FIGS. 1 and 2, the process reaction chamber 1 and the plasma generation chamber 2 are made of pure aluminum, and the electrostatic chuck 12 and the like provided therein are made of alumina porcelain with few impurities. It is configured. Thereby, it is possible to sufficiently prevent the occurrence of heavy metal contamination caused by plasma irradiation. [Effects of the Invention] As described above, according to the present invention, wafers are taken out one by one from a cassette containing semiconductor wafers, loaded into a process reaction chamber held at a vacuum pressure, and a predetermined wafer A single-wafer processing type semiconductor wafer processing apparatus for performing a process, and thereafter carrying out a wafer from a process reaction chamber and storing the wafer in a cassette, comprising a wafer holding mechanism and a wafer processing means for holding the wafer at a predetermined position in the chamber. Process reaction chamber, first and second lock chambers equipped with vacuum evacuation systems installed in series with the process reaction chamber, and a first lock chamber between the process reaction chamber and the first lock chamber. A vacuum gate valve that individually separates each passage between the lock chamber and the second lock chamber and between the second lock chamber and the outdoor atmosphere side, and a second lock that takes out a wafer from a cassette disposed outside the chamber. A handling mechanism provided outside the room for loading a wafer into the inside, a relay transfer mechanism provided inside the second lock chamber for receiving and holding one wafer carried from the outside, and a second transfer mechanism provided for the second lock room. And a handling mechanism for transferring the wafer between the relay transfer mechanism on the lock chamber side and the wafer holding mechanism in the process reaction chamber. By adopting a configuration in which the chamber is evacuated every time a wafer is loaded, foreign substances such as dust are prevented from entering the process reaction chamber from the atmosphere side, and the reliability of the wafer process processing is greatly improved. Moreover, since the wafer transfer is performed while the wafer storage cassette is placed outside the room, the idle time required for loading and unloading the cassette can be omitted as compared with the conventional apparatus, and the first and second lock chambers, and By installing two independent wafer transfer systems, including their accessories, for loading and unloading wafers into and from the process reaction chamber, wafer loading and unloading operations can be performed in parallel to increase productivity. For example, it is possible to provide a practical semiconductor wafer processing apparatus that can sufficiently cope with a mass production scale in terms of processing performance, reliability, and throughput.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are block diagrams of different embodiments of the present invention, and FIG. 3 is a block diagram of a conventional semiconductor wafer plasma processing apparatus. In each figure, 1: process reaction chamber, 2: plasma generation chamber, 9: evacuation system,
11: wafer holding mechanism, 13: cassette, 14: wafer, 15: first
Lock chamber, 16: second lock chamber, 17, 18: evacuation system, 19,2
0,21: Vacuum gate valve, 22: Relay transfer mechanism, 23: Handling mechanism.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Koichi Nakagawa               1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa                 Fujitsu Limited (72) Inventor Masahiko Toki               1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa                 Fujitsu Limited (72) Inventor Atsuhiro Tsukune               1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa                 Fujitsu Limited                (56) References JP-A-60-249329 (JP, A)                 JP-A-60-246635 (JP, A)

Claims (1)

(57) [Claims] The wafers are taken out one by one from the cassette containing the semiconductor wafers and carried into a process reaction chamber maintained at a vacuum pressure, where predetermined wafer processing is performed, and thereafter, the wafers are carried out of the process reaction chamber and stored in the cassette. A semiconductor wafer processing apparatus of a single-wafer processing type, comprising: a wafer holding mechanism for holding a wafer at a predetermined position in a chamber; a process reaction chamber equipped with wafer processing means; First and second lock chambers equipped with the evacuated exhaust system, between the process reaction chamber and the first lock chamber, between the first lock chamber and the second lock chamber, and between the second lock chamber and the outdoor A vacuum gate valve for individually partitioning each passage between the atmosphere side and a handling provided outside the chamber for taking out a wafer from a cassette disposed outside and loading the wafer into the second lock chamber; And a relay delivery mechanism provided in the second lock chamber for receiving and holding one wafer carried in from outside, a relay delivery mechanism provided in the first lock chamber and located on the side of the second lock chamber, and And a handling mechanism for transferring a wafer to and from a wafer holding mechanism in a process reaction chamber, wherein the first lock chamber is constantly evacuated and the second lock chamber is evacuated every time a wafer is loaded. Semiconductor wafer processing apparatus. 2. The processing apparatus according to claim 1, wherein
(1) A semiconductor wafer processing method, wherein two sets of equipment for loading and unloading wafers are installed in a process reaction chamber, as a set of equipment including a second lock chamber and its attached equipment. apparatus. 3. 2. The semiconductor wafer processing apparatus according to claim 1, wherein the process reaction chamber is made of pure aluminum.