JPS60261101A - Film resistance element and method of producing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a membrane resistive element used in integrated circuits and the like, and a method for manufacturing the same.

[Prior art]

Generally 1. Tantalum nitride (TaN), =
Chromium (Ni-Cr), silicon monoxide containing chromium, polysilicon, etc. are used.

Since the resistivity of these materials cannot be changed significantly, in order to achieve the desired resistance value, it is necessary to select the most suitable material and then adjust it by adjusting the film thickness and area of the resistor. Furthermore, when forming a plurality of resistors with significantly different resistance values on the same substrate, it was necessary to use combinations of different materials depending on the required resistance value.

However, since we are trying to incorporate a film resistance element into an integrated circuit consisting of a fine pattern, the film thickness of the resistor 2
There is a natural limit to the area, and even if an optimal material is selected, the range of resistance values that can be adjusted is narrow, and there is a drawback that the circuit membrane is subject to significant restrictions.

[Summary of the invention]

The present invention has been made in view of the above-mentioned problems, and its objectives are to obtain a membrane resistance element in which a desired resistance value can be freely selected over a wide range;
Another object of the present invention is to obtain a manufacturing method that can extremely easily form this film resistance element.

In order to achieve this object, the present invention uses a metal silicide to which nitrogen is added as a resistor of a film resistance element. In addition, in order to form this film resistance element, metal silicide or metal and silicon are used as targets.
Sputtering is performed in argon gas containing nitrogen gas.

Hereinafter, the present invention will be described in detail along with examples.

〔Example〕

FIG. 1 is a sectional view of a GaAs integrated circuit showing one embodiment of the present invention. On the Ga, As substrate 10, there is a MESFE 72 having a structure using a Schottky barrier in the gate part of the FET.
0 is formed, and the film resistance element 12 according to the present invention is formed in the space next to it.

In this embodiment, the resistor of the film resistance element 12 is made of tungsten silicide doped with nitrogen, and is made of semi-insulating GaA
They are formed on the s-substrate 10, the silicon nitride film 14, and the silicon oxide film 16, respectively.

Note that the MESF, ET20 is an n-type high concentration source region 22. Similarly, an n-type high concentration drain region 24, an n-type active layer 26. Source electrode 28. Torrein electrode 30. It is constituted by a Schottky gate electrode 32.

The film resistance element 12 is formed by the following spuckling method. That is, tungsten silicide doped with nitrogen is deposited on the GaAs substrate 10 by reactive sputtering using tungsten silicide and mixing nitrogen gas in argon gas.

Thereafter, patterning is performed using a [CF4+02] plasma etching method, a lift-off method, or the like, and the deposited tungsten silicide is removed leaving a desired region, thereby forming the film resistive element 12.

The resistance value of the film resistance element 12 can be controlled by changing the amount of nitrogen added to the tungsten silicide. Specifically, it is controlled by the nitrogen gas flow rate ratio during sputtering.

Figure 2 shows that the discharge power is ioow and the total gas pressure is 5mTor.
3 is a graph plotting the resistivity of a nitrogen-doped tungsten silicide film formed as a film resistance element 12 on a silicon oxide film 16 against the nitrogen gas flow rate ratio during sputtering under conditions r. Note that the resistivity at a nitrogen gas flow rate ratio of 0% is the resistivity of tungsten silicide to which no nitrogen is added.

As can be seen from this figure, the resistivity of the nitrogen-doped tungsten silicide can be controlled continuously and over a wide range by changing the nitrogen gas flow rate ratio. In particular, it can be seen that the resistivity can be controlled over a wide range even when the resistivity is 10 -2 Ωm or more, which is often used in resistive elements.

Note that nitrogen-doped tungsten silicide can also be used as an electrode in portions with low resistivity, and the Schottky gate electrode 32 of this embodiment is formed of nitrogen-doped tungsten silicide. In this case, by adjusting the area, the film resistance element 12 and the Schottky gate electrode 32 are
It is also possible to form them simultaneously by performing two deposition processes.

The film resistance element 12 and the Schottky gate electrode 32 are
If they can be formed simultaneously by lfj product processing, the number of manufacturing steps will be reduced, which is advantageous for mass production.

Furthermore, it has already been shown that nitrogen-added tungsten silicide does not react with a substrate such as GaAs or Sin even when subjected to high-temperature heat treatment at about 800° C., and high-temperature processing after deposition is also possible.

Note that in this example, nitrogen-doped tungsten silicide is used as the nitrogen-doped metal silicide.
Molybdenum instead of tungsten.

Even when tantalum, niobium, etc. are used, the resistivity can be controlled continuously and over a wide range by targeting molybdenum silicide, tantalum silicide, niobium silicide, etc., and changing the nitrogen gas flow rate ratio, as in the case of tungsten. .

Further, in this example, the film resistance element is formed on the GaΔS integrated circuit, but other compound semiconductor integrated circuits and S
It goes without saying that a similar film resistance element can be formed in a semiconductor device using i.

Further, in this embodiment, tungsten silicide was used as the target for sputtering, but a similar film resistance element can also be formed by performing sputtering simultaneously using two targets of tungsten and silicon. For film resistance elements using nitrogen-doped molybdenum silicide, nitrogen-doped tantalum silicide, and nitrogen-doped niobium silicide, simultaneous sputtering is performed using molybdenum and silicon, tantalum and silicon, and niobium and silicon as targets, respectively. .

Note that although Fig. 2 shows the resistivity when the nitrogen gas flow rate ratio is changed from 0% to approximately 30%, even higher resistivity can be obtained by increasing the nitrogen gas flow rate ratio up to 100%. It is possible to obtain a resistor of

〔Effect of the invention〕

Since a metal silicide doped with nitrogen is used as the child resistor, film resistive elements having a wide range of desired resistance values can be freely selected and formed in the integrated circuit. Therefore, the degree of freedom in circuit design is expanded, making it easier to create excellent integrated circuits.

Furthermore, according to the manufacturing method of the present invention, metal silicide or metal and silicon are used as a couget, and sputtering is performed in argon gas containing nitrogen gas, so that the desired resistance value can be obtained by simply selecting the nitrogen gas flow rate ratio appropriately. It is possible to easily form a film resistance element of

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a GaAs integrated circuit showing an embodiment of the present invention, and FIG. 2 is a graph showing the relationship between the nitrogen gas meteor ratio and the resistivity of nitrogen-doped tungsten silicide. 10... GaAs substrate, 12... Film resistance element, 14
...Silicon nitride film, 16...Silicon oxide film. Patent applicant: Nippon Telegraph and Telephone Public Corporation Agent: Masaki Yamakawa (and one other person) Approximately 1 figure 0 Adjacent 2 figures 0 10 20 30 4O N2 gas boiler ('/,) Procedural amendment (voluntary) Commissioner of the Japan Patent Office 9゛1 "ζ97.56" 1. Indication of the case Patent Application No. 116629 of 1982 2. Name of the invention Film resistance element and its manufacturing method 3. Person making the amendment Relationship to the case Patent Applicant name (name ) (422) Nippon Telegraph and Telephone Public Corporation 5, Detailed explanation of the invention column 6 of the specification subject to amendment, Contents of the amendment (1) After “Materials” on page 2, lines 6 to 7 of the specification Add "wo". (2) r 10-2 Ωm” on page 5, line 13 of the same book
Correct it as l(i”Ω spit”.

Claims (2)

[Claims] (1) A film resistance element characterized by having a resistor made of metal silicide added with nitrogen. (2) Forming a resistive film on the substrate by sputtering in argon gas containing nitrogen gas using metal silicide or metal and silicon as a cuget, and then removing this resistive film leaving a desired area. A method for manufacturing a membrane resistance element characterized by: