JP2001237159A - Method of manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device of high reliability, where a wafer can be subjected to a lithography process, being kept in a good state even after the wafer on which a wiring metal layer of laminated structure is formed is stored for a long term. SOLUTION: In a step 11, transistor elements are formed on a semiconductor wafer, and a laminated wiring metal film composed of a prescribed wiring metal layer and an antireflection film or a barrier layer is formed on all the surface of a wafer. Being kept in this state, the semiconductor wafer is stored in a storehouse for a long term (step 12). The semiconductor wafer is taken out of the storehouse after an optional storage time, if necessary (step 13). Thereafter, as shown in a step 14, the semiconductor wafer delivered from a storehouse undergoes a rinsing process before the semiconductor wafer delivered from a storehouse is subjected to a lithography process. Thereafter, the semiconductor wafer is subjected to a lithography process in a step 15 for the formation of a required wiring pattern on the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing method, and more particularly to a semiconductor device which is applied to maintenance and management of reliability in the case where an intermediate semiconductor wafer having a laminated wiring structure formed in close contact with the entire surface is stored for a long period of time. It relates to a manufacturing method.

[0002]

2. Description of the Related Art In an LSI manufacturing process (wafer process), it is sometimes necessary to maintain an intermediate state in which a wiring metal layer is deposited on the entire surface after a transistor element is formed. Such a wafer is subjected to a lithography process using a mask (ROM mask) according to a customer's request, for example, and a desired ROM (read-only storage device) is realized.

A wiring metal layer is generally an aluminum wiring layer mainly containing Al as a main component. At the portion where the aluminum wiring layer is connected to Si forming the transistor element, a barrier layer is required as a base. With this barrier layer, the spike phenomenon of Al and the precipitation of Si can be prevented. Further, it is necessary to form an antireflection film on the uppermost surface of the wiring metal layer. This antireflection film can prevent halation in the lithography process.

[0004] The former barrier layer is, for example, a TiN / Ti laminate, and the latter antireflection film is, for example, a TiN layer. If the wiring metal layer having such a laminated structure is formed on the entire surface of the wafer and stored for a long period of time, the accumulation of the stress of the TiN layer proceeds.

[0005]

When a lithography process is performed on a wafer on which the wiring metal layer is formed on the entire surface, a scrubber process is performed before the lithography process. The scrubber treatment here is to spray an ultrasonic water flow over the entire surface of the wafer. This achieves the purpose of improving the adhesion of the resist and removing particles before the lithography step.

[0006] The scrubber process is a process that involves considerable impact on the wafer surface. Conventionally, even after a wiring metal layer having a laminated structure is formed on the entire surface of a wafer and stored for a long period of time, a scrubber process has been performed after entering a lithography process.

[0007] If the accumulation of stress in the TiN layer due to long-term storage and the impact of the scrubber treatment are superimposed, the damage to the wafer becomes considerably large. In the worst case, a part of the TiN layer or the Al layer on the contact hole or the via hole is blown off. As a result, there is a problem in that the yield is reduced, for example, particles are generated even if no defect occurs.

The present invention has been made in view of the above circumstances, and a wiring metal layer having a laminated structure is formed on the entire surface of a wafer, and the lithography process is performed while maintaining a good state even after long-term storage. It is an object of the present invention to provide a method for manufacturing a highly reliable semiconductor device.

[0009]

According to the method of manufacturing a semiconductor device of the present invention, a semiconductor wafer having a laminated wiring metal film formed of a predetermined wiring metal layer and an antireflection film or a barrier layer formed on an entire surface is optionally used. A lithography step after a storage period, wherein the semiconductor wafer after the storage period is subjected to a water washing step before the lithography step.

Further, the method of manufacturing a semiconductor device according to the present invention comprises:
A method in which a semiconductor wafer having a laminated wiring metal film including a predetermined wiring metal layer and an anti-reflection film or a barrier layer formed on the entire surface is transferred to a lithography step after an arbitrary storage period, wherein the laminated wiring After forming the metal film, the semiconductor wafer goes through a scrubber process and enters a storage period.

Further, a method of manufacturing a semiconductor device according to the present invention
A method in which a semiconductor wafer having a laminated wiring metal film formed of a predetermined wiring metal layer and an anti-reflection film or a barrier layer formed on the entire surface is transferred to a lithography step after an arbitrary storage period, wherein the storage period A step of performing a scrubber process on the semiconductor wafer after forming the laminated wiring metal film before the step, and a step of performing a water washing process on the semiconductor wafer after the storage period and before shifting to a lithography process. It is characterized by having done.

According to each of the semiconductor device manufacturing methods of the present invention, the scrubber treatment involving a large impact on the wafer surface is not introduced after at least the laminated wiring metal layer is formed on the entire surface of the wafer and stored for a long time.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow chart showing main steps of a method for manufacturing a semiconductor device according to a first embodiment of the present invention. After forming the transistor elements on the semiconductor wafer in step 11, a laminated wiring metal film including a predetermined wiring metal layer and an antireflection film or a barrier layer is formed on the entire surface of the wafer. In this state, it is stored for a long time in the storage (step 12). After an arbitrary storage period, the semiconductor wafer is unloaded as needed (step 13). Thereafter, as shown in step 14, the semiconductor wafers that have been unloaded before going to the lithography process undergo a water washing process. Thereafter, in step 15, a lithography process is performed to form a desired wiring pattern.

FIG. 2 is a cross-sectional view of a portion of the semiconductor wafer before the lithography step in FIG. On a semiconductor wafer 101, a transistor element 102 and an interlayer insulating film 103 are formed. A predetermined contact hole 104 is formed in the interlayer insulating film 103. A barrier metal 105 made of, for example, a TiN / Ti laminate is formed including the contact hole 104, and an aluminum wiring layer 106 is formed thereon. T on the aluminum wiring layer 106
An anti-reflection film 107 made of an iN layer is formed on the entire surface.

The washing step in step 14 is different from the scrubber washing which exerts a large physical effect, and is treated by, for example, a Dip-type rinse with pure water. Therefore, as shown in FIG.
No part of the layer or aluminum wiring is blown away.

According to the method of the above embodiment, a scrubber treatment involving a large impact on the wafer surface is not performed after a long-term storage of a wafer having a stress of the TiN layer. Thereby, even after long-term storage, it is possible to shift to the lithography process while maintaining a good state. In addition, the purpose of improving the adhesion of the resist and removing the particles before the lithography step is achieved.

FIG. 3 is a flow chart showing main steps of a method for manufacturing a semiconductor device according to a second embodiment of the present invention. After transistor elements are formed on the semiconductor wafer in step 21, a laminated wiring metal film including a predetermined wiring metal layer and an antireflection film or a barrier layer is formed on the entire surface of the wafer. Immediately after the formation of the laminated wiring metal film, a scrubber treatment is performed (step 22). The scrubber treatment here is spray cleaning by an ultrasonic water flow. As a result, the particles are stored for a long time in the storage with the particles removed (step 23). Then, after an arbitrary storage period, the semiconductor wafer is unloaded as needed (step 24). Thereafter, a lithography process is performed in step 25,
A desired wiring pattern is formed.

According to the method of the above-mentioned embodiment, it is preferable to carry out scrubber cleaning as soon as possible after the formation of the laminated wiring metal film, preferably before storing the wafer for a long period of time, where there is concern about the stress of the laminated wiring metal film (lamination including the TiN layer). Remove particles. Thus, similarly to the configuration shown in FIG. 2, even after being stored for a long time, it is possible to shift to the lithography process while maintaining a good state. In addition, the purpose of improving the adhesion of the resist and removing the particles before the lithography step is achieved.

FIG. 4 is a flow chart showing steps of a main part of a wafer in a method of manufacturing a semiconductor device according to a third embodiment of the present invention. After forming the transistor elements on the semiconductor wafer in step 31, a laminated wiring metal film including a predetermined wiring metal layer and an antireflection film or a barrier layer is formed on the entire surface of the wafer. Immediately after the formation of the laminated wiring metal film, a scrubber process is performed (step 32). The scrubber treatment here is spray cleaning by an ultrasonic water flow. As a result, the particles are stored in the storage for a long time in a state where the particles have been removed (step 33). Then, after an arbitrary storage period, the semiconductor wafer is unloaded as needed (step 34). Thereafter, as shown in step 35, a water washing step is performed in order to wash the unloaded semiconductor wafer again before shifting to the lithography step. In step 36, a lithography process is performed to form a desired wiring pattern.

According to the method of the above embodiment, before the wafer is stored for a long period of time, where there is a concern about the stress of the laminated wiring metal film (lamination including the TiN layer), it is preferable to carry out scrubber cleaning as soon as possible after forming the laminated wiring metal film. The particles are removed, and the wafer is washed again with water before the lithography process even after the delivery. Thus, similarly to the configuration shown in FIG. 2, even after being stored for a long time, it is possible to shift to the lithography process while maintaining a good state.
In addition, the purpose of improving the adhesion of the resist and removing the particles before the lithography step is achieved.

[0021]

As described above, according to the present invention, in each method of manufacturing a semiconductor device, the scrubber treatment involving a large impact on the wafer surface is performed by forming a laminated wiring metal layer for forming at least different kinds of metal layers in close contact. It is not introduced after being formed on the entire surface of the wafer and stored for a long period of time, and the purpose of improving the adhesion of the resist and removing particles before the lithography process is achieved. As a result, a highly reliable semiconductor device capable of shifting to the lithography process while maintaining a good state even after being stored for a long period of time after forming a laminated wiring metal layer for closely forming a heterogeneous metal layer. A manufacturing method can be provided.

[Brief description of the drawings]

FIG. 1 is a flowchart showing main steps of a method for manufacturing a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of a part of the semiconductor wafer before a lithography step related to FIG. 1;

FIG. 3 is a flowchart showing main steps of a method for manufacturing a semiconductor device according to a second embodiment of the present invention;

FIG. 4 is a flowchart showing main steps of a method for manufacturing a semiconductor device according to a third embodiment of the present invention;

[Description of Symbols] 11 to 15, 21 to 25, 31 to 36 Processing step 101 Semiconductor wafer 102 Transistor element 103 Interlayer insulating film 104 Contact hole 105 Barrier metal 106 Aluminum wiring layer 107 Antireflection film

Claims (3)

[Claims] 1. A method of transferring a semiconductor wafer having a laminated wiring metal film including a predetermined wiring metal layer and an antireflection film or a barrier layer formed on the entire surface to a lithography step after an arbitrary storage period. And subjecting the semiconductor wafer, which has been stored for a period of time before shifting to the lithography step, to a rinsing step. 2. A method for transferring a semiconductor wafer having a laminated wiring metal film including a predetermined wiring metal layer and an antireflection film or a barrier layer formed on the entire surface thereof to a lithography step after an arbitrary storage period. A method of manufacturing a semiconductor device, comprising: entering a storage period through a scrubber process step on the semiconductor wafer after the formation of the laminated wiring metal film. 3. A method of transferring a semiconductor wafer, in which a laminated wiring metal film including a predetermined wiring metal layer and an antireflection film or a barrier layer is formed on the entire surface, to a lithography step after an arbitrary storage period. Performing a scrubber process on the semiconductor wafer after forming the laminated wiring metal film before the storage period, and performing a water washing process on the semiconductor wafer before shifting to a lithography process after the storage period. A method of manufacturing a semiconductor device, comprising: