JPH1168049A - Mos transistor resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a MOS transistor resistance in which a MOS transistor resistance value can be changed by an Al interconnection at the final stage of a semiconductor-device manufacturing process by a method wherein a plurality of places to which the Al interconnection can be connected are formed in parts in which diffusion regions protrude from a polysilicon gate. SOLUTION: A plurality of places to which an Al interconnection can be connected are formed in parts in which diffusion regions protrude from a polysilicon gate. The resistance value of a MOS transistor resistance is changed by the parts to which the Al interconnection can be connected. That is to say, when the MOS transistor resistance value is to be increased, it can be increased in such a way that the Al interconnection connected to an output 2 is connected to an output 3 or an output 4. When the Al interconnection is connected to the output 3, a value of 3R is obtained. When the Al interconnection is connected to the output 4, a value of 4R is obtained. In addition, when the MOS transistor is to be decreased, it can be decreased in such a way that the Al interconnection connected to the output 2 is connected to an output 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method of wiring a resistance of a MOS transistor.

[0002]

2. Description of the Related Art The purpose of using the resistance of a conventional MOS transistor is as follows: signal delay, feedback resistance in an oscillation circuit,
There are pull-down and pull-up of terminals, and the resistance value is designed with the calculated value to achieve those purposes.

[0003] However, the resistance value calculated at the beginning of the design may change the resistance value due to a design change or the like.

In addition, there is a case where the resistance value of the MOS transistor is changed due to a design error or a wiring resistance connected to the MOS transistor resistance, and the resistance value cannot be obtained as expected.

Hereinafter, a method of changing a resistance value by a MOS transistor resistance in a conventional example will be described with reference to the drawings.

FIG. 2 shows a basic MOS transistor resistance. The MOS transistor resistance is determined by the length of the diffusion region in the polysilicon gate.

FIG. 3 shows a configuration when the MOS transistor resistance is reduced. Compared to FIG. 2, the length of the diffusion region in the polysilicon gate is about 1/2, and the resistance value is also about 1/2.
Becomes

FIG. 4 shows a configuration when the MOS transistor resistance is increased. As compared with FIG. 2, the length of the diffusion region in the polysilicon gate is about three times, so that the resistance value is also about three times.

When the resistance value of the MOS transistor is changed as described above, the length of the diffusion region in the polysilicon gate is changed by changing either the diffusion region or the polysilicon to change the resistance value.

[0010]

When the resistance value of the MOS transistor is changed as shown in FIGS. 3 and 4, diffusion is performed in the initial step of the manufacturing process of the MOS transistor or polysilicon is used in the middle step.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to change the MOS transistor resistance value by the AL wiring at the end of the semiconductor device manufacturing process.

[0012]

In order to achieve the above object, a method for wiring a MOS transistor resistor according to the present invention is characterized in that a plurality of locations to which an AL wiring can be connected are provided in a portion where a diffusion region protrudes from a polysilicon gate. I do.

[0013] A plurality of MOS transistor resistors A
By enabling connection of the L wiring, the resistance value can be easily changed. Also, the semiconductor device manufacturing process can be shortened by changing from the AL process, which is the final process, as compared with the diffusion process, which is the initial process of the semiconductor device manufacturing process, and the polysilicon process, which is the middle process.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of a MOS transistor resistor according to the present invention. As shown in FIG. 1, a plurality of locations where the AL wiring can be connected are provided at portions where the diffusion region protrudes from the polysilicon gate. The resistance value of the MOS transistor resistance is changed depending on the location to which this AL wiring can be connected.

The MOS transistor resistance required for design is determined, and the length of the diffusion region in the polysilicon gate is determined so as to attain the value. Further, a change range of the resistance value of the MOS transistor is determined. A resistance value corresponding to a change range of the resistance value of the MOS transistor is prepared. Although it is easy to reduce the resistance value of the MOS transistor, it is possible to increase it only in a range prepared in advance. If it is necessary to exceed the resistance value prepared in advance, it is necessary to change all about ten masks constituting the MOS transistor resistance as in the prior art.

Output 1 from the current input, output 2 from the output 1,
The resistance values R of the outputs 2 to 3 and the outputs 3 to 4 are the same. The initially set resistance value is 2R when the AL wiring is connected to the input and output 2 in FIG.

In order to increase the resistance value of the MOS transistor, it is possible to connect the AL wiring connected to the output 2 to the output 3 or the output 4. When the AL wiring is connected to the output 3, a value of 3R is obtained. When the AL wiring is connected to the output 4, a value of 4R is obtained.

In order to reduce the resistance value of the MOS transistor, the AL wiring connected to the output 2 can be connected to the output 1. When the AL wiring is connected to the output 1, a value of 1R is obtained.

That is, by providing a plurality of outputs, M
The OS transistor resistance can be easily changed by the AL wiring. The MOS transistor resistance can be changed by changing one AL mask.

The step of using the AL mask is a MOS
Since this is the final step in the process of creating the transistor resistance, the period for changing the resistance value of the MOS transistor is reduced.

[0021]

As is apparent from the above description, the MOS transistor resistance value in the present invention is compared with the diffusion step as the initial step of the MOS transistor resistance manufacturing step and the AL step as the final step as compared with the polysilicon step as the middle step. It can be easily changed by changing from.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a MOS transistor resistor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a basic configuration of a conventional MOS transistor resistor.

FIG. 3 is a diagram showing a configuration in which a conventional MOS transistor has a reduced resistance value.

FIG. 4 is a diagram showing a configuration in which the resistance value of a conventional MOS transistor is increased.

Claims (2)

[Claims] 1. A MOS transistor having a resistance of MO
A MOS transistor resistor whose resistance value is changed by changing the AL wiring in one mask in the AL process without changing about 10 masks constituting the S transistor resistance. 2. A MOS transistor resistor which obtains a plurality of resistance values with one MOS transistor resistor by providing a plurality of resistor outputs in the MOS transistor resistor.