JPS59144164A - Manufacture of hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To prevent the disconnection due to the leakage of compound solution of resistance pattern or improper pinholes by locally exposing the vicinity of the connection of a resistance circuit network connected to an anodic oxidation continuity circuit. CONSTITUTION:A resistor tantalum thin film 5 is bonded on a substrate 1, and a resistor pattern is formed by selective etching. A resist pattern 3 exposed on the surface of the resistance pattern in the vicinity of the resistor pattern connection unit is formed, an anodic oxidation is performed on an etching stop layer 4, and an anodic oxidation layer 6 is formed. Then, the exposed resistance pattern unit is oxidatively broken to become disconnected state. Then, electrode metal film 7 which is made of nichrome alloy, palladium and gold is bonded to the entire substrate, and the oxidized breakdown part is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a hybrid integrated circuit, and more particularly to a method of manufacturing a high quality tantalum thin film RC circuit with excellent reliability.

Conventionally, a method for manufacturing a thin film circuit consisting of a thin film capacitor and a thin film resistor formed on the same substrate is as follows.

First, a beta or al-7 artantalum layer is deposited on an insulating substrate such as glass or ceramic by sputtering,
The tantalum layer is selectively etched to form the entire desired capacitor pattern. Next, the tantalum layer in the area defined to be used as a capacitor is selectively anodized to form an etching stop layer, and then a resistor thin film is deposited over the entire substrate by sputtering. Forms adhesion. Next, a desired resistor network is formed by etching all seven thin film resistors for the resistor, and then a predetermined portion of the capacitor region is anodized again using a positive photoresist as a protective mask, and the capacitor film is form. The protective mask is peeled off using a known method. Next, an upper electrode made of nichrome alloy, palladium, and gold is deposited on the entire substrate obtained above by vacuum evaporation or magnetron sputtering, and a desired pattern is formed by photoresist treatment. A thin film circuit is manufactured by adjusting the desired resistance value of the tantalum resistor I by anodizing the tantalum surface or by laser trimming.

However, according to the above-mentioned manufacturing method, a major problem arises, especially in pattern design where the trend towards finer patterns is progressing. That is, as miniaturization progresses, capacitor and resistor patterns may become more complex, and as miniaturization accompanies a reduction in the space for forming a resistor network, the following difficulties arise in pattern design.

Thin film circuits satisfy all quality characteristics by forming multiple capacitors and resistors on the same substrate. Moreover, miniaturization naturally makes the resistor network denser, resulting in a resistor network that is inevitably connected to a chemical circuit pattern previously formed for fully anodizing the capacitor. In this case, as described above, when a predetermined region to become a capacitor is anodized using a 7-otoresist as a protective mask, the pressure resistance, adhesion, etc. of the protective mask are very important. In other words, since anodization is performed in an acidic solution for 1 to 2 hours, the mask formed on the resistor circuit may be defective, causing surface leaks, etc., and when the solution touches the resistive film surface, a sudden current flows. In particular, oxidation damage occurs, the resistance circuit is disconnected, and the thin film circuit board itself becomes defective. This phenomenon is an unavoidable problem in the above method.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a hybrid integrated circuit that corrects the drawbacks of the above-mentioned manufacturing methods.

That is, after forming a resistor network, when anodic oxidizing a capacitor pattern portion in a predetermined area in an acidic solution using a 7-otoresist as a protective mask, the protective mask pattern is added to the predetermined capacitor region portion, and a By calculating and forming the vicinity of the connection part of the resistor circuit that is formed by being connected to the conductive circuit, by applying a concentrated voltage at the same time as the start of the anodizing process, it is oxidized and destroyed, and the chemical formation of the resistor circuit pattern part is performed. Eliminating disconnections due to liquid leaks, etc.? This is a method for manufacturing a hybrid integrated circuit.

Hereinafter, the present invention will be explained about the production of tantalum thin film RC circuit. As an example,
This is explained in detail in the drawings.

FIGS. 1 to 1 are cross-sectional views in the manufacturing process of a hybrid integrated circuit according to the present invention. A tantalum thin film 2 having a thickness of about 400 OA is formed by sputtering on a thoroughly cleaned partially undulated insulating substrate 1 (FIG. 1). Next, a tantalum-based thin film 2 is formed using a known photoetching method.
using an etching solution to form the desired capacitor pattern (FIG. 2). Next, a Borge type photoresist 3, for example, OF'PR-7RF manufactured by Tokyo Ohka Co., Ltd., is applied to a thickness of about 12 to 15 μm, and then prebaked at 100°C for 30 minutes in an infrared drying oven, and the resist film is selectively exposed to light. Then, using a developer such as 0FPR, -7R manufactured by Tokyo Ohka Chemical Co., Ltd., the photosensitive area is dissolved and a desired resist pattern is formed in which the tantalum thin film to be the dielectric is exposed (FIG. 3). Next, the substrate is anodized in a 0.0196 citric acid solution at a constant voltage of 150 V for 10 minutes to form an oxide film at the portions that are to become the electrolyte, and an etching stop layer for the mental etching solution. 4 (Figure 4). Next, a tantalum-based thin film 5 for a resistor is deposited by sputtering.
It is deposited on the entire surface of the 0OA substrate (Fig. 5), and a desired resistor pattern is formed by selective etching using a mixed solution of hydrofluoric acid and nitric acid (Fig. 6).Next, under the same conditions as the etching stop layer formation method. A resist pattern 3 is formed which exposes the surface of the etching stop layer and the surface of the resistor pattern in the vicinity of the connecting portion of the resistor pattern connected to the conductive circuit pattern for anodic oxidation by about 40 μm (FIG. 7). % citric acid solution under constant voltage anodization conditions of 200 V for 2 hours, the etching stop layer is anodized to form an anodic oxide film 6.
Simultaneously with the start of anodic oxidation, a voltage under the conditions for forming the etching stop layer is rapidly applied to the exposed resistor pattern portion without the etching stop layer, causing the exposed resistor pattern portion to be oxidized and destroyed, resulting in a disconnection state (Fig. 3). ). Next, a metal film 7 for an upper electrode made of a synichrome alloy, palladium, and gold is deposited on the entire substrate by sputtering, and a well-known 7
By using etching techniques (FIG. 9), a circuit network including capacitors and resistors is obtained. Finally, stabilization heat treatment in the atmosphere? After this, the p resistance value is adjusted using a laser trimming method.

As described above, according to the method of the present invention, the resistance pattern connected to the conductive circuit pattern for anodization is destroyed by rapidly applying a concentrated voltage to the vicinity of the connection part at the same time as the start of anodization, causing the resistance pattern to break. There are no breaks or bottle hole defects due to liquid leaks.Furthermore, when forming the pattern of the upper electrode film, it is easy to connect the broken wires.Production of highly reliable hybrid integrated circuits with no change in quality. becomes possible.

Furthermore, it becomes easier to design a resistor network as miniaturization and miniaturization occur.

[Brief explanation of the drawing]

FIG. 1 to FIG. 1B are cross-sectional views of the manufacturing process of a hybrid integrated circuit for explaining the present invention in detail. In the figure, 1... Partially dalesed ceramic substrate, 2... Tantalum thin film, 3...
・Positive photoresist, 4...Etching stop layer, 5...Tantalum thin film for resistor, 6.
...Anodic oxide film, 7...Nichrome, )
'd, ku purchased and deposited.

Claims (1)

[Claims] When forming an RC circuit on an insulating substrate, a resistor connected to the conductive circuit for anodizing is used in the step of selectively anodizing a desired pattern portion that will become a capacitor in an acidic solution using a 7-otoresist process. A method of manufacturing a hybrid integrated circuit characterized by locally exposing the vicinity of a connection part of a circuit network.