KR19990009140A - Manufacturing method of electrical connection device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrical connection device, and more particularly, to a method of making an electrical connection device including a multilayer polymer layer and a metal layer used in electronic or semiconductor applications. In order to improve adhesion between polymers such as polyimide and benzocyclobutene having excellent dielectric properties and conductive metal layers adhered thereon, an ion beam having an energy of 100 to 1500 eV is irradiated to the polymer layer to generate reactive gas around the sample. The present invention relates to a method for manufacturing an electrical connection apparatus by surface treatment of a polymer layer by flowing and increasing adhesion to a metal attached by vapor deposition or sputtering thereon.

Description

Manufacturing method of electrical connection device

The present invention relates to a method for manufacturing an electrical connection device, and more particularly, to a method for increasing adhesion by using an ion beam in an electrical connection device including a multilayer polymer layer and a metal layer used in electronic and semiconductor applications.

The general trend in microelectronic circuits is changing towards demanding high performance at low cost. In an integrated circuit, the interconnection structure is closely related to performance and miniaturization. Recently, due to the high density of the multi-chip module-on circuit, it has received a lot of attention, and the high-density, thin-film multi-chip module packaging has very high application potential because of its fine dimensional control, low dielectric constant polymer, and easy processing. It is a high skill.

Multichips usually have a multilayer structure, and the metal layers are separated by an organic dielectric layer. Some polymer materials are known to achieve high density and high performance in electronic components such as multichips.

The thermal and mechanical properties of dielectric materials greatly affect the performance and reliability of circuits. High thermal stability and low thermal expansion are usually desirable for circuit processing and performance.

In the manufacturing process of a multichip module, it is considered sufficient to withstand about 300 ° C. In a silicon-based circuit, it must be able to withstand a temperature of about 400 ° C. The thermal stability of such polymeric dielectric materials determines the maximum temperatures the circuit can withstand during processing and use.

Polyimide and cyclobutadiene (specifically benzocyclobutarene (BCB)) have been widely used as dielectric materials for circuits. U.S. Patent No. 5,196,103 describes the preparation and use of benzocyclobutane in detail and is known to have better water absorption and dielectric constant than polyimide. Polyimide or cyclobutene in the form of a film is particularly preferable as an insulating material because of its excellent electrical and thermal properties. But when the polymers are in the form of thin films, another important problem arises: their adhesion to other materials that interface with the polymer (usually an electrically conductive metal layer).

In order to solve the above-mentioned adhesion problem, that is, adhesion promoters have been used in order to maintain a reliable adhesion between polyimide and cyclobutene with other inorganic layers. In the case of a polymer material, there is a method in which a monomer or a prepolymer is applied to a surface before bonding the two materials, and then the prepolymer is cured, and thus a complete chemical bond can be formed between the two materials to be bonded. However, it is known that the adhesion between the polymer and the metal layer is limited by using only an adhesion promoter such as the above-described prepolymer.

Many attempts have been made to solve such adhesion problems, and one method is to deposit or sputter a tie layer between the polymer and the metal to enhance adhesion. This method spoils the polymer layer because it is sputtered with high energy density plasma or reactive ions, and sputtering diffuses the bonding layer metal into the polymer layer, thereby limiting the role of the polymer layer and ultimately improving the performance of the dielectric layer. You can make it impossible to exercise. In addition, a thick bonding layer thickness of about 200 kHz to 1000 kHz can lower the high frequency electrical conductivity of the conductive metal film.

Accordingly, the present invention provides a sufficient surface between the metal conductive layer and the insulating polymer in the multilayer electrical connection device in which the metal conductive layers are separated by the insulating polymer, and the surface treatment is carried out within a range in which the role of the polymer is not limited. It is a technical problem to provide a method for producing an electrical connecting device having excellent adhesive force during the use of the connecting device or during the manufacture of the electrical connecting device.

1 is a schematic longitudinal cross-sectional view of an ion beam processing apparatus used in the manufacture of the electrical connection device of the present invention.

1 --- vacuum chamber 1a --- vacuum vent

2 --- reactive gas inlet 2a --- sample holder

3 --- Ion Gun 3a --- Shutter

According to the present invention, in the manufacture of an electrical connection device, a bonding layer is used or used after surface treatment of a polymer, such as a cyclobutene-based or polyimide, using an ion beam having an energy of 100 to 1500 V in a reactive gas atmosphere. Without sputtering or depositing a metal such as copper, thereby improving the adhesive force between the polymer layer and the metal layer.

Hereinafter, the present invention will be described in more detail.

The present invention relates to bonding a conductive metal layer to a dielectric material such as polyimide or cyclobutene. 1 is a schematic diagram of a device used in the present invention. 1 is a portion of an ion gun or ion source 3 comprising a gas inlet portion 2 for introducing a reactive gas into the vacuum chamber 1 and a portion for ionizing the gas and a portion for accelerating the ionized gas. divided. Reference numeral 1a denotes a vacuum exhaust port, reference numeral 2a denotes a sample holder, and 3a denotes a shutter.

In the ion beam treatment apparatus shown in FIG. 1 used in the present invention, a gas is ionized by introducing a gas into an ion gun 3 mounted in the vacuum chamber 1, and the ionized particles are scanned toward the sample surface and simultaneously As a result, a reactive gas such as oxygen is allowed to flow around the sample through the inlet 2. The gas introduced into the ion gun 3 is preferably argon, nitrogen, oxygen, or the like. In addition, nitrogen and oxygen are used as the gas introduced into the reactive gas inlet (2). The ion gun 3 used in the present invention may use a cold-hallow cathode type, but other types of ion guns are possible.

General conditions for surface modification are as follows.

Chamber vacuum degree: 1 x 10 ^-4 ∼ 1 x 10 ^-6 Torr

Ion beam energy: 100 to 1500 eV

Ion ^{dose: 1 x 10 14 ~ 1 x} 10 16 ions / ㎠

1 and the configuration of the present invention carried out under the above conditions is as follows. The surface treatment of the polymer with low energy ion beams provides sufficient adhesion between the dielectric material and the metal layer deposited on it by mechanical bonding and chemical bonding due to the formation of a reactor on the polymer surface. In this case, in order to enhance adhesion, the interfacial bond layer forming the carbide may be deposited or sputtered in the middle. The energy range of the ion beam sputtering in the above range is an energy range such that the surface thickness variation range (surface roughness) of the polymer surface is 50 Å or less.

For cyclobutene and polyimide used in the present invention, US Pat. No. 4,540,763 and J. Adhesion Sci. Tech. Vol. 1, No. 4, pp. 341-347 (1987), respectively. Methods for preparing cyclobutene are described in US Pat. Nos. 4,407,633, 4,831,172, and 4851603. The polyimide or cyclobutene used in the present invention has a low dielectric constant (polyimide: 3.1, cyclobutene <3), excellent stability at about 300 ° C., and planarization of 90% or more.

Hereinafter, the present invention will be described in detail with Examples and Comparative Examples.

Examples 1-9

Polyimide or benzocyclobutane-divinyl tetramethyl siloxane (BCB-DVS) films were coated on silicon wafers. That is, a 55% BCB-DVS prepolymer solution or a polyimide prepolymer solution was coated on a wafer that was cleaned by ionized water or plasma. The coated wafer was crosslinked at 250 ° C. for at least 40 minutes in a nitrogen atmosphere. Then, the wafer was cut to a size of 2 cm × 2 cm with a diamond saw, washed with ethanol, and subjected to ion beam treatment under the conditions shown in Table 1 using the ion beam apparatus described above. The pressure of the ion beam chamber when no reactive gas was added was about 1 × 10 ⁻⁵ torr. The ion gun used in this example used a cold-hallow cathode type. After ion beam treatment, the titanium layer and the copper layer were sputtered or evaporated using an electron gun. The adhesion of copper was measured by the tensile test. Table 1 shows the adhesion values for the samples obtained using sputtering. The thickness of copper which is a conductive metal layer was 1 micrometer.

Comparative Examples 1 to 7

It was carried out similarly to the above Example except that the conditions shown in Table 1 below.

The results of Comparative Examples 1 to 6 were written together in the following Table 1.

Polymer Type Ion Gun Injection Gas and Energy Reactive Gas and Chamber Vacuum Ion (ions / ㎠) Bonding layer (Ti) thickness Adhesive force (psi) Example 1 BCB-DVS Ar, 500eV O ₂ (5x10 ^-5 torr) 1 x ^{10 15} 100 4900 Example 2 Ar, 300eV O ₂ (5x10 ^-5 torr) 1 x ^{10 15} 100 5320 Example 3 O ₂ , 500eV O ₂ (5x10 ^-5 torr) 1 x ^{10 15} 100 5740 Example 4 Ar, 500eV O ₂ (5x10 ^-5 torr) 1 x ^{10 15} 200 4760 Example 5 Ar, 500eV O ₂ (5x10 ^-5 torr) 1 x 10 ¹⁶ 100 5740 Example 6 Ar, 500eV O ₂ (5x10 ^-5 torr) 1 x 10 ¹⁷ 100 5460 Example 7 Polyimide Ar, 500eV O ₂ (5x10 ^-5 torr) 1 x ^{10 15} 100 7000 Example 8 Ar, 300eV O ₂ (5x10 ^-5 torr) 1 x ^{10 15} 100 7560 Example 9 O ₂ 500 eV O ₂ (5x10 ^-5 torr) 1 x 10 ¹⁶ 100 8540 Comparative Example 1) BCB-DVS unused unused 0 100 5.0 Comparative Example 2) Ar, 500eV Unused (5x10 ^-4 torr) 1 x ^{10 15} 0 320 Comparative Example 3) Ar, 500eV Unused (5x10 ^-4 torr) 1 x ^{10 15} 100 4200 Comparative Example 4) Polyimide unused unused 0 100 55 Comparative Example 5) Ar, 500eV Unused (5x10 ^-4 torr) 1 x 10 ¹⁶ 0 520 Comparative Example 6) Ar, 500eV Unused (5x10 ^-4 torr) 1 x ^{10 15} 100 5900 Comparative Example 7) Ar, 1500 eV O ₂ (5x10 ^-4 torr) 1 x ^{10 15} 100 3000

As shown in Comparative Examples and Examples of Table 1, it can be seen that the electrical connection device according to the present invention exhibits excellent adhesion between the polymer dielectric layer and the copper layer when the semi-negative gas is injected while scanning the ion chamber.

In the present invention, an electrical connection device including a multilayer polymer layer and a metal layer used in electronic or semiconductor applications is irradiated with an ion beam to a polymer layer while flowing reactive gas around a sample to treat the surface of the polymer layer, and then depositing it thereon. Adhesion with the metal deposited by sputtering is increased to obtain excellent adhesion between the polymer dielectric layer and the copper layer.

Claims (3)

In the manufacture of the electrical connection device, after the surface treatment of a polymer, such as a cyclobutene-based or polyimide, by using an ion beam having an energy of 100 to 1500 V in a reactive gas atmosphere, copper is used with or without a bonding layer. And sputtering or depositing a metal, such as to improve the adhesion between the polymer layer and the metal layer. The method of claim 1, wherein the gas entering the ion gun (3) is argon, nitrogen, oxygen, and the reactive gas entering the sample surroundings is nitrogen, oxygen. The method according to claim 1, wherein the energy range of the ion beam sputtering is such that the surface thickness change width (surface roughness) of the polymer surface is 50 kW or less.