JP2000012776A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a defective capacitor from occurring due to an electrical discharge that occurs through a dielectric film. SOLUTION: An upper electrode 114 is formed above a semiconductor board 104, a wiring 14 electrically connected to the lower electrode of a capacitor 108 is formed, and a first and a second pad 16 and 18 connected to the wiring 14 at different points are formed. Thereafter, a wafer test is carried out in a final manufacturing process, where wafer probes are put on the first and second pad 16 and 18 to be energized apply a voltage between them, whereby the wiring 14 is fused. Therefore, even if the capacitor 108 is charged up in a manufacturing process, electric charge is discharged from the capacitor 108 through the wiring 14 at once, so that a defective capacitor which occurs due to an electric discharge that takes place through a dielectric film included in the capacitor 108 can be avoided, and a manufacturing yield can be restrained from decreasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device including a capacitor.

[0002]

2. Description of the Related Art In manufacturing a semiconductor device, a capacitor (also referred to as a capacitance here) is often formed on a semiconductor substrate together with various circuit elements such as a transistor element and a resistor. FIG. 4 is a cross-sectional view of a main part showing a typical example of a capacitance forming portion in a semiconductor device. As shown in FIG.
In the semiconductor device 102, a field oxide film 106 is first formed on a semiconductor substrate 104 made of, for example, silicon, and a capacitor 108 is formed thereon. Capacity 108
Is composed of a lower electrode 110, a dielectric film 112, and an upper electrode 114. On the field oxide film 106,
A lower electrode 110 made of a conductive material such as aluminum is formed, a dielectric film 112 made of a dielectric material is formed thereon, and an upper electrode 114 made of a conductive material such as aluminum is formed thereon.

[0003]

However, conventionally, when manufacturing such a semiconductor device 102, there is a case where a capacitor 108 having a required capacitance cannot be formed due to a capacity leak, and the manufacturing yield is reduced. Was invited. In particular, as shown in the circuit diagram of FIG. 5, when one end (upper electrode 114) of the capacitor 108 is connected to one end of a high resistance 116 made of polysilicon formed on the semiconductor substrate 104, This problem often occurred.

[0004] The inventor of the present invention examined the defective capacitor formation portion in detail to identify the cause, and found that
Discharge traces are observed on the dielectric film 112.
It has been found that the charge is abnormally accumulated in the capacitor 108 during the manufacturing, and the accumulated charge is temporarily discharged through the dielectric film 112. It is considered that charge accumulation occurs in the step of etching aluminum on the semiconductor substrate 104 and the step of growing a passivation film.

An object of the present invention is to provide a method of manufacturing a semiconductor device in which the occurrence of defective capacity due to such discharge is prevented.

[0006]

According to the present invention, in order to achieve the above object, a first conductive film made of a conductive material is formed on a semiconductor substrate, and a first conductive film made of a dielectric material is formed on the first conductive film. A method of manufacturing a semiconductor device in which a dielectric film is formed, a second conductive film made of a conductive material is formed on the dielectric film, and a capacitor is formed on the semiconductor substrate. A step of forming a wiring made of a conductive material over the semiconductor substrate to be electrically connected to the first conductive film, and performing one or more steps of the semiconductor substrate;
Cutting the wiring.

That is, in the present invention, a wiring made of a conductive material for connecting the second conductive film to the first conductive film is formed on a semiconductor substrate, and then, for example, at the final stage of the manufacturing process, this wiring is formed. Disconnect. Therefore, during production,
Even if electric charges are accumulated in the capacitance formed by the first and second conductive films and the dielectric film, the electric charges are immediately discharged through the wiring. As a result, it is possible to avoid the occurrence of defective capacitance due to discharge through the dielectric film, and to prevent a reduction in manufacturing yield.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view for explaining an example of a method for manufacturing a semiconductor device according to the present invention, and FIGS. 2 and 3 are circuit diagrams showing main parts of a semiconductor device manufactured by the method for manufacturing a semiconductor device according to the embodiment. is there. In addition,
In the drawing, the same elements as those in FIGS. 4 and 5 are denoted by the same reference numerals.

The capacitance 108 of the semiconductor device 2 shown in FIG. 1 is manufactured in a conventional manner. That is, as shown in FIG. 4, a field oxide film 106 is first formed on a semiconductor substrate 104 made of, for example, silicon, and a lower electrode 110, a dielectric film 112, and an upper electrode 114 are sequentially formed thereon in this order. Is done. The lower electrode 110 is electrically connected to the semiconductor substrate 104 (ground) at a location (not shown).

Thereafter, in this embodiment, as shown in FIG. 1, a wiring for electrically connecting the upper electrode 114 (the second conductive film according to the present invention) to the semiconductor substrate 104, and thus to the lower electrode 110. 14 are formed. This wiring 14
For example, aluminum can be used as the material. Further, in the present embodiment, when the wiring 14 is formed, the first and second pads 16 and 18 connected to different portions of the wiring 14 are formed simultaneously.

Then, in this embodiment, as shown in FIG. 2, a high resistance 116 (not shown in FIG. 1) made of polysilicon having one end connected to the upper electrode 114 is formed. Further, various elements are formed on the semiconductor substrate 104 by etching aluminum, growing a passivation film, and the like. Thereafter, a wafer test is performed as the final stage of the manufacturing process. At this time, a wafer probe needle is connected to the first and second pads 16 and 18.
To the first and second pads 16,
The wiring 14 is blown by applying a current between the wires 18. FIG. 3 shows a state after the wiring 14 has been blown in this step. In this state, the capacitor 108 exhibits its original function.

Therefore, in the method of manufacturing a semiconductor device according to the present embodiment, even if a charge is accumulated in the capacitor 108 during the manufacture, the charge is immediately discharged through the wiring 14. As a result, it is possible to avoid the occurrence of defective capacitance due to the discharge through the dielectric film 112 (FIG. 4), and it is possible to prevent a reduction in manufacturing yield.

As described above, the present invention has been described based on the embodiment. However, this is merely an example, and the present invention can be implemented in various forms without being limited to this example. For example, in the present embodiment, the wiring 14
Is cut by energization, but it is of course possible to cut the wiring 14 by selective etching. In that case, the first and second pads 16 and 18 do not need to be formed.

[0014]

As described above, according to the present invention, a first conductive film made of a conductive material is formed on a semiconductor substrate, and a dielectric film made of a dielectric material is formed on the first conductive film. ,
A method of manufacturing a semiconductor device in which a second conductive film made of a conductive material is formed on the dielectric film to form a capacitor on the semiconductor substrate, wherein the second conductive film is formed of the first conductive film Forming a wiring made of a conductive material on the semiconductor substrate, and performing one or more steps on the semiconductor substrate, and then cutting the wiring. Features.

Therefore, in the method of manufacturing a semiconductor device according to the present invention, a wiring made of a conductive material for connecting the second conductive film to the first conductive film is formed on the semiconductor substrate. At this stage, this wiring is cut. Therefore, during manufacture, even if electric charge is accumulated in the capacitance formed by the first and second conductive films and the dielectric film, the electric charge is immediately discharged through the wiring. As a result, it is possible to avoid the occurrence of defective capacitance due to discharge through the dielectric film, and to prevent a reduction in manufacturing yield.

[Brief description of the drawings]

FIG. 1 is a plan view for explaining an example of a method for manufacturing a semiconductor device according to the present invention.

FIG. 2 is a circuit diagram showing a main part of a semiconductor device manufactured by a method of manufacturing a semiconductor device according to an embodiment;

FIG. 3 is a circuit diagram showing a main part of a semiconductor device manufactured by a method of manufacturing a semiconductor device according to an embodiment, and showing a state after wiring is cut;

FIG. 4 is a cross-sectional view of a main part showing a typical example of a capacitance forming portion in a conventional semiconductor device.

FIG. 5 is a circuit diagram illustrating a periphery of a capacitor formed in the semiconductor device of FIG. 4;

[Explanation of symbols]

2, 102: semiconductor device; 104: semiconductor substrate, 1
06 ... field oxide film, 110 ... lower electrode, 11
2 ... dielectric film, 114 ... upper electrode, 14 ... wiring, 1
6 first pad, 18 second pad, 116
... high resistance, 108 ... capacity.

Claims (11)

[Claims] 1. A semiconductor device comprising: a first substrate made of a conductive material;
Forming a conductive film of a dielectric material on the first conductive film, forming a second conductive film of a conductive material on the dielectric film, and forming a conductive film on the semiconductor substrate. A method of manufacturing a semiconductor device forming a capacitor, wherein a step of electrically connecting the second conductive film to the first conductive film and forming a wiring made of a conductive material on the semiconductor substrate; A step of cutting the wiring after performing one or more steps on the semiconductor substrate. 2. The method of manufacturing a semiconductor device according to claim 1, wherein in the step of cutting the wiring, a current is applied to the wiring to blow the wiring. 3. The method according to claim 2, wherein the cutting of the wiring is performed in a wafer test process. 4. A step of forming first and second pads connected to different portions of the wiring on the semiconductor substrate, wherein the step of cutting the wiring includes a step between the first and second pads. 3. The method according to claim 2, wherein a current is applied to the wiring by applying a voltage. 5. The method of manufacturing a semiconductor device according to claim 4, wherein a voltage is applied to the first and second pads using a wafer probe needle. 6. The method according to claim 1, wherein in the step of cutting the wiring, the wiring is cut by selective etching. 7. The method according to claim 1, wherein the one or more steps include one or both of an aluminum etching step and a passivation film growing step. 8. The method according to claim 1, wherein the wiring is made of aluminum. 9. The method according to claim 1, wherein the second conductive film is connected to one end of a high resistance formed on the semiconductor substrate. 10. The method according to claim 9, wherein said high resistance is formed of polysilicon. 11. The method according to claim 1, wherein a field oxide film is formed between the semiconductor substrate and the first conductive film.