JP2592511B2 - Vertical semiconductor manufacturing system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of semiconductor devices, and more particularly to a vertical semiconductor manufacturing system capable of simultaneously performing various film formation and etching processes in the manufacture of semiconductor devices. It is about.

[Conventional technology]

In the manufacture of a semiconductor device, it is necessary to form various films, for example, a silicon oxide film, a silicon nitride film, polysilicon and the like are grown by vapor phase. Plasma may be used to lower the growth temperature. In each case, the growth temperature is different and the type of gas used is also different. Therefore, a dedicated reaction apparatus is required, and the wafer to be processed must be transported to each dedicated reaction apparatus in a state of being housed in a cassette, and the storage of the wafer during this time must take measures to prevent contamination. .

As an example of vapor phase growth, in classical epitaxial growth, a carbon susceptor was placed in a vertical reaction tube, and silicon chloride gas was supplied from above. This apparatus is of a single-wafer type, and in order to improve the number of processed wafers, an apparatus having a susceptor capable of setting a large number of wafers around has been developed.

At present, hot-wall type CVD is used for the vapor phase formation of the above-mentioned various films including silicon oxide film.
The apparatus is mainly used, and wafers are arranged upright in a horizontal reaction tube to improve the number of wafers that can be processed at one time.

In the vertical furnace and the horizontal furnace described above, if it is intended to further improve the number of processed wafers, there is no measure other than arranging a plurality of apparatuses themselves. Systems for supplying cassettes have been proposed.

Further, in the horizontal furnace, as a diffusion furnace, an apparatus for supplying a wafer cassette to each of a plurality of furnace core tubes arranged side by side for a long time as a diffusion furnace is provided to improve the number of processed wafers.

At the same time, semiconductor devices are becoming smaller and more complicated in structure. Due to subtle differences in the flow of reactant gas and temperature distribution, uniformity of distribution between wafers and distribution within wafers can be maintained. There have been no cases. That is, in the above hot wall type CVD apparatus, the reactant gas (2
(Combination of two or more kinds). Therefore, it is difficult to adjust uniformly in a batch. In particular, when forming silicon oxynitride, the reaction gas is monosilane,
It becomes three components, ammonia and nitric oxide, and its adjustment becomes more and more difficult.

Therefore, a need has arisen for a single-wafer apparatus in which each wafer is placed in a precisely controlled atmosphere and processed with good reproducibility. The single-wafer apparatus has an advantage that it can easily cope with an increase in the diameter of a wafer and can flexibly cope with various manufacturing processes with one apparatus, but the number of sheets that can be processed at one time is limited. In order to improve this, a multi-chamber system has been proposed, in which multiple chambers are provided in one apparatus and the same processing is performed simultaneously.
It has begun to be adopted in equipment.

Further, in recent reports, a multi-process apparatus having a function capable of executing a different type of process in each chamber instead of the same process in a plurality of chambers has appeared. For example, as shown in FIG. 3, by preparing four process chambers and performing plasma CVD, reduced pressure CVD, plasma etching, and sputter etching, the interlayer insulating film forming process of the multilayer wiring can be performed uniformly and in one apparatus. It is said that it can be automatically formed flat.

[Problems to be solved by the invention]

The above multi-process apparatus has a structure in which a polygonal or circular vacuum chamber is provided at the center, and a plurality of independent exhaust system process chambers are arranged around the vacuum chamber, and the number of chambers that can be installed is limited. It is not possible to add more. In order to further increase the number of chambers, the same system must be installed. Since the entire apparatus is arranged in a plane, there is a disadvantage that the floor area is increased.

In addition, since there is only one robot for moving wafers into and out of the chambers for a large number of chambers, it is impossible to set or remove wafers at the same time.

[Means for solving the problem]

In order to solve the above-mentioned problems, in the present invention, the process chambers (2) are installed in each step position of the partitioned space in the vertical direction, and the front surfaces of the plurality of vertically arranged process chambers (2) are arranged. A vertical semiconductor manufacturing system is characterized in that a wafer load / unload mechanism is provided on the side.

[Action]

According to the present invention, the conventional multi-process apparatus has a planar arrangement configuration, it is impossible to add more chambers than specified, and the loading and loading of wafers into each chamber is not possible.
Considering that there is a problem that unloading cannot be performed in parallel, the results of repeated studies have been made to improve the throughput of a single sheet type even with a small floor area, and to make it extremely simple to add chambers. In order to make effective use of expensive clean rooms, the concept of a vertical system in which each process chamber is vertically stacked has been reached. That is, in a preferred embodiment of the present invention, a pair of a process chamber and an exhaust pump is stacked and fixed vertically. Thus, the expansion of the chamber is facilitated. Each chamber has an internal structure suitable for plasma CVD, sputtering, thermal CVD with plasma self-cleaning, and dry etching, for example, a parallel plate type electrode (gas supply) structure, so that the internal pressure is suitable for each process. Next, the exhaust pump is operated. A load / unload mechanism for loading and unloading wafer cassettes is provided on the front side of the process chamber opposite to the exhaust pump side. A cassette elevator to be installed. Further, a cassette storage chamber is provided at another position on the front side of the process chamber of each stage.

The cassette elevator is connected to each process chamber, performs an elevator operation in a vertical direction, and carries a cassette to an arbitrary position.

At the front position of each process chamber, a wafer loading / unloading mechanism for loading / unloading a wafer into / from each chamber is provided. That is, from the transported wafer cassette,
A wafer transfer mechanism (robot) is provided that takes out wafers one by one and sends them to a process chamber, and after a predetermined process is completed, transfers the processed wafers to a cassette in a cassette storage chamber. This transfer mechanism may be of a type in which the wafer is moved in the horizontal direction by placing the wafer on the tip of a flat bar, or may be a telescopic robot. More preferably, in order to reduce the heating time in the chamber, a wafer mounting table is provided at the front position of each process chamber, and a heater is built in this table,
It is preferable to perform preheating, and then transfer the wafer to the chamber by the above-described load / unload mechanism.

The cassette storage chamber is provided at another position on the front side of the process chamber, and stores processed wafers,
Take out each cassette from this position.

The cassette storage chamber may be independent in each stage, but is preferably a mechanism that can be integrated in the uppermost stage or the lowermost stage.

Cassette elevator and wafer transfer mechanism (robot)
In addition, the cassette storage chamber may have a common front outer wall surface, and it is preferable that the operator inserts and removes the cassette toward this wall. Such a system is called a so-called through-the-wall system.

A high-frequency oscillating power supply is required for plasma processing, and a reactive gas system for processing is also required. These are placed facing each other with the above-mentioned support as the center, and should be attached to the support in a balanced manner. Good. The aforementioned chamber,
The exhaust pump, oscillating power supply and gas system are all located on one side of the wall, making repair work and expansion work easier. In some cases, a pipe may be provided on the side wall of the chamber for the purpose of integrating mechanical equipment, so that a so-called pipe IC may be achieved. Similarly, the oscillation power supply can be made smaller, integrated with the matching box, and installed in the upper space of the process chamber. Further, the inside of the column may be hollow and connected to the exhaust pipe at each position, and in parallel exhaust, the column itself may be used as an exhaust pipe to contribute to improvement of exhaust efficiency.

Practically, the clean room has a height of 3 to 3.5 m, and if designed well, it is possible to connect 6 to 7 chambers.

〔Example〕

A vertical semiconductor manufacturing system according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a cross-sectional view showing the configuration of a vertical system according to an embodiment of the present invention. Reference numeral 1 denotes a pole serving as a support of the entire apparatus. This pole has a balance between each process chamber 2 and a pump 3. It is mechanically fixed. The pump 3 may be a conventional type of pump, the exhaust side of which is led to the outside air via a duct 4 (FIG. 2).

The pair of the process chamber 2 and the pump 3 is the first
Although three sets are illustrated in the example of the figure, this can be selected according to a predetermined number of processes. Further, the process chamber 2 can be provided as a dedicated chamber for any of sputtering, plasma CVD, thermal CVD, and dry etching. However, from the viewpoint of multi-process, continuous processing of different processes (for example, flattening process). Various
It is possible to have an internal structure that can execute CVD and etch-back processes. In the example shown in the figure, an upper electrode 5 that can spray a reactive gas in a shower and a heater that can heat a wafer to a predetermined temperature are provided. A chamber having a built-in lower electrode 6 is installed in each process chamber.

At the top of the process chamber 2, a matching box 7 is arranged.
High frequency generated from oscillation power supply 8 (generally 13.75 MHz)
Performs a function of impedance matching when the voltage is applied to the upper electrode 5.

The supply of the reaction gas to the process chamber is introduced into the chamber through the inside of the electrode 5 as described above. However, the supply of the gas is not limited to this, and the supply of the gas is performed from the left end side of the matching box 7. Can also.

In any case, piping for the supply of the reaction gas is necessary, and the piping 9 is mounted on the support column at a time. However, as shown in FIG. And fix it mechanically. In FIG. 1, the pair of the oscillation power supply 8 and the gas system 9 is omitted for simplicity.

Next, the transfer mechanism 11 of the semiconductor wafer 10 to be processed will be described. In this embodiment, as is apparent with reference to the top view of FIG. 2, a cassette elevator mechanism is provided on the front side of the process chamber 2 and extends in a vertical direction, and a wafer cassette is moved to each chamber position. Transport.

Similarly, on the front side, on the front side of each process chamber 2, wafers are taken out one by one from the transported cassette, and the wafers 10 are set in the process chambers through the gates 12. A wafer transfer mechanism (robot) 14 for taking out the wafer and storing the wafer in a cassette storage chamber 13 provided at each stage position is provided.

Needless to say, the gate 12 is located between the transfer mechanism side and the process chamber 2 so that the two can be air-tightly separated, and the gate is opened when a wafer is introduced / exited, so that the wafer can pass through.

Therefore, in the examples of FIGS. 1 and 2, the cassette elevator mechanism 11 has a vertical column shape extending over the upper and lower process chambers, and the wafer transfer mechanism (robot) and the cassette are horizontally arranged at each process chamber position. Partitions surround the storage room, minimizing the required space and saving time required for exhaust.

Although not shown, a cassette load lock mechanism is provided at the lowest stage of the cassette elevator 11,
A plurality of cassettes are inserted using this load lock mechanism, and the processed cassettes are taken out of each cassette storage chamber.

 Next, a method of using the apparatus of this embodiment will be described.

A plurality of cassettes are installed in the cassette storage room with a load lock mechanism at the bottom of the cassette elevator 11,
The cassette transport mechanism is evacuated from the location marked as evacuated at the bottom of the figure. Each process chamber is evacuated to a predetermined pressure by each pump 3 in advance. When the exhaust in the cassette transport mechanism is completed, remove one cassette from the cassette storage box and
Is transported to, for example, the uppermost position and locked at that position. Next, the transport mechanism is lowered to the lowest stage, the next cassette is taken out from the cassette storage box, transported to the intermediate stage position by the transport mechanism, and locked at that position. Further, the transport mechanism is lowered to the lowermost stage, the next cassette is taken out from the cassette storage box, transported to the lowermost position of the process chamber by the transport mechanism, and locked at that position.

The wafer transfer robot 14 at each stage position takes out the wafers one by one from the cassette locked at the position, and sets the wafer 10 on the lower electrode 6 in the process chamber by the above-described procedure. When the predetermined process is completed, the wafer is taken out and the cassette storage chamber 13 is removed.
To be stored. This operation is repeated by the number of wafers to complete the processing in each process chamber.

In the above embodiment, the same or different processes are executed for the wafers in each cassette. However, a cassette elevator can be used so that different processes can be sequentially executed.

In the above-described embodiment, the poles are provided to fix the respective chambers. However, it is also possible to arrange the shelves in the vertical direction, and to install the chambers and the like in the respective shelves. In addition, each chamber is independently exhausted so that different processing can be performed. However, when processing is performed under the same conditions in all chambers, only one pump may be used.

〔The invention's effect〕

As described above, in the present invention, since the system is configured by vertically stacking the multi-process chambers, the floor area can be reduced. In addition, because it is a vertical system that attaches a process chamber to a pole or a shelf, expansion is easy, and while one of the chambers is being repaired, the process can be performed in another chamber There is an advantage that the repair of the entire apparatus can be simplified.

Of course, as long as the cassette is transferred inside the transfer mechanism, there is no adhesion of dust on the wafer. In the case of the so-called through-the-wall method, when the cassette is removed from the cassette storage chamber 13 and set in the cassette storage box again and the next process is executed, the adhesion of dust does not become a problem as far to the left.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the configuration of a vertical system according to this embodiment of the present invention. FIG. 2 is a top view of the system of FIG. 1, and FIG. 3 is a conventionally proposed multi-process system. FIG. In the figure, 1 is a pole serving as a support of the entire apparatus, 2 is a process chamber 2, 3 is a pump 3, 5 is an upper electrode, 6 is a lower electrode 6, 7 is a matching box, 8 is an oscillation power supply, 9 is a gas system, Reference numeral 10 denotes a semiconductor wafer, 11 denotes a cassette elevator, 12 denotes a gate, 13 denotes a cassette storage room, and 14 denotes a wafer transfer robot.

Claims (1)

(57) [Claims] 1. A process chamber (2) is vertically arranged at each step position of a partitioned space, and a wafer is loaded and unloaded on the front side of the plurality of vertically arranged process chambers (2). A vertical semiconductor manufacturing system comprising a mechanism.