RU2671543C1 - Method of creating a bilateral topological pattern in metallization on substrates with through metallized micro-holes - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: when forming a topological pattern by lithography for applying and drying the resist, the substrate is initially dipped into a resist, followed by drying successively at a temperature lower than the drying temperature of the resist and the drying temperature of the resist and removing the resist. Then the resist is sprayed with a spray method first to one side of the substrate, followed by drying, and then similarly to its other side. Size of the resist drops applied by the spray method is d<<d, where d– diameter of the drop of resist, d– diameter of the through-hole micro-opening.EFFECT: method of creating a two-sided topological pattern of metallization is proposed to increase the manufacturability and reproducibility in the formation of a bilateral topological pattern in metallization on substrates with through metallized micro-holes.1 cl, 3 dwg, 2 tbl

Description

The invention relates to the field of microelectronics technology, and in particular to methods specifically designed for the manufacture or processing of microstructural devices or systems. The invention can be used in the manufacture of 3D - MEMS structures, multichip systems in a housing with a structural arrangement of crystals one above the other, as well as microwave devices based on waveguides integrated into the substrate.

Known methods of forming a topological pattern using a number of methods of applying a resist (Moro W. Microlithography: Principles, methods, materials. In two parts. Translated from English under the editorship of R.Kh. Timerov. Moscow. 1990): dipping, aerosol method centrifugation, roller application.

The disadvantages of the known methods of applying a resist when forming a topological pattern in metallization on substrates with through metallized micro-holes include low manufacturability, which means irreproducibility:

- when the resist is centrifuged on the metallization of substrates with through metallized microholes, “comets” arise due to irreproducible flow of the resist into the holes, and when the topological pattern is etched, the metallization of the through holes can be etched,

- when applying the aerosol method of applying resist or applying resist with rollers, masking in the through holes of metallization is uneven, which leads to the possibility of etching when forming a topological pattern,

- when applying a resist by dipping, a resist coating wedge is formed in thickness due to the draining of the resist under the action of gravity, which leads to the irreproducibility of obtaining a topological pattern.

Atomique, публикация 2011 г.) известен способ нанесения полимерного слоя из раствора на подложки, содержащие углубления. Для заполнения углублений применяется планаризация слоя полимера с помощью цилиндра, помещенного на плоскую часть поверхности подложки. Недостатком известного способа является низкая технологичность и, как следствие, низкая воспроизводимость процесса нанесения из-за механического воздействия цилиндра на поверхность подложки, что не позволяет обрабатывать хрупкие подложки и/или перфорированные подложки (со сквозными отверстиями) из-за неконтролируемого выдавливания полимера через отверстия. Наиболее близким техническим решением к заявляемому является способ изготовления полупроводниковых устройств, предусматривающий спреевое нанесение покрытия на подложку с отверстиями, известный из патентной заявки JP S57 145 325 (Nippon Electric Co., публикация 1982 г.). Недостаток данного способа является его низкая технологичность при обработке подложек со сквозными отверстиями.From US Pat. No. 8,067,060 (Commisariat a

Atomique, 2011 publication) discloses a method for applying a polymer layer from a solution to substrates containing depressions. To fill the recesses, planarization of the polymer layer is applied using a cylinder placed on a flat part of the surface of the substrate. The disadvantage of this method is the low processability and, as a consequence, the low reproducibility of the deposition process due to the mechanical action of the cylinder on the surface of the substrate, which does not allow brittle substrates and / or perforated substrates (with through holes) to be processed due to uncontrolled extrusion of the polymer through the holes. The closest technical solution to the claimed is a method of manufacturing semiconductor devices, providing spray coating on a substrate with holes, known from patent application JP S57 145 325 (Nippon Electric Co., 1982 publication). The disadvantage of this method is its low manufacturability when processing substrates with through holes.

Thus, the expected technical result of the proposed invention is to increase manufacturability and reproducibility in the formation of a two-sided topological pattern in metallization on substrates with through metallized micro-holes.

The proposed method for manufacturing a two-sided topological pattern in the metallization of substrates with metallized microholes involves the formation of a topological pattern on the metallized surfaces of the substrates. The substrate is dipped into a resist, followed by the first drying and removal of the resist, and then the resist is applied by the spray method on the side of the substrate, followed by the second drying, with further exposure, development, subduing, etching of the metallization and removal of the resist. Unlike the analogue, the first drying of the substrate after dipping into the resist is performed sequentially at a temperature lower than the drying temperature of the resist, and then at the drying temperature of the resist. For example, at a temperature equal to half the temperature of the drying of the resist for at least 4 hours and at the temperature of drying the resist for at least 2 hours. Removing the resist is performed by chemical-mechanical treatment with a solvent of the resist. Using a spray method, a resist is applied to one side of the substrate, followed by final drying of this side, and to the other side of the substrate, followed by final drying of this side of the substrate. The size of the resist droplets applied spreevym method is _to d << d _{of holes} where _to d - diameter of the resist drops, um, _holes d - diameter of the through microperforations, um.

The features and essence of the claimed invention are explained in the following detailed description, illustrated by the drawings, which show the following.

In FIG. 1 is a flowchart of a proposed method for manufacturing a two-sided topological pattern on the metallized surfaces of substrates with through metallized micro-holes. In FIG. 1 shows the sequence (az) of the implementation of the proposed method:

- applying a resist to the metallized surface of the substrate with through metallized micro-holes by dipping method (Fig. 1, a),

- drying the resist sequentially in two stages at a temperature equal to half the drying temperature of the resist for at least 4 hours and at a drying temperature of the resist for at least 2 hours (Fig. 1, b),

- removal of the resist from the metallized surfaces of the substrate by chemical-mechanical treatment with a solvent of the resist (Fig. 1, c),

- applying a resist spreevym method on the front side of the substrate at a droplet size of resist _to d << d _{of holes} where _to d - diameter of the resist drops, _holes d - diameter of the through microperforations (Figure 1 g.),

- drying of the resist after application to the front side of the substrate (Fig. 1, d),

- applying a resist spreevym method to the reverse side of the substrate at a droplet size of resist _to d << d _{of holes} where _to d - diameter of the resist drops, _holes d - diameter of the through microperforations (Fig 1, e.),

- drying of the resist after application to the back of the substrate (Fig. 1, g),

- double-sided lithography, including known stages for the manufacture of a two-sided topological pattern in metallization on substrates with through metallized micro-holes (Fig. 1, h).

In FIG. 2 (a-e) presents in detail the sequence of the proposed method in the form of cross-sections of a substrate with metallized surfaces and through holes.

In FIG. 2, a, 2, d, 2, e the following positions are indicated:

1 - substrate

2 - through holes

3 - metallization of through holes,

4 - metallized surface of the substrate,

5 is a topological drawing of a resist on the metallized surfaces of the substrate,

6 is a two-sided topological drawing in metallization on a substrate with through metallized micro-holes,

7 - resist on the metallized surfaces of the substrate with through metallized micro-holes, formed by dipping and drying successively in two stages at a temperature equal to half the temperature of drying the resist for at least 4 hours and at the drying temperature of the resist for at least 2 hours,

8 - resist is formed by sequentially spreevym on the front side of the substrate at a droplet size of resist _to d << d _holes, drying spreevym method on the back side of the substrate at a droplet size of resist _to d << d _{of holes} where _to d - diameter of the resist drops, _holes d - diameter of the through _holes microperforations d - diameter of the through microperforations and drying.

In FIG. 2 presents the following cross sections of the substrate in the process of implementing the proposed method:

- a cross section of the original substrate with metallized surfaces and through holes (Fig. 2, a),

- the cross section of the substrate with metallized surfaces and through holes in the metal after applying the resist to the metallized surfaces of the substrate with through holes in the metal by dipping and drying the resist in series in two stages at a temperature equal to half the drying temperature of the resist for at least 4 hours and at the drying temperature of the resist for at least 2 hours (Fig. 2, b),

- the cross section of the substrate with metallized surfaces and through-holes after removing the resist from the metallized surfaces of the substrate by chemical-mechanical treatment with a solvent of the resist (Fig. 2, c),

- the cross-section of the substrate with metallized surfaces and through holes in the hole after applying the resist by the spray method on the front side of the substrate with a droplet size d _to << d _holes , drying the resist after applying on the front side of the substrate, spraying the resist on the back side of the substrate with the droplet size resist _to d << d _{of holes} where _to d - diameter of the resist drops, _holes d - diameter of the through microperforations and drying after applying the resist onto the back side of the substrate (Figure 2, g.)

- the cross section of the substrate with metallized surfaces and through-holes after forming a topological pattern in a resist on the metallized surfaces of the substrate with double-sided lithography (Fig. 2, e),

- the cross-section of the substrate with metallized surfaces and through micro-holes after the formation of a topological pattern on the metallized surfaces of the substrate with double-sided lithography (Fig. 2, f).

In FIG. Figure 3 shows a micrograph of a fragment of a two-sided topological pattern in metallization on a substrate with through metallized micro-holes.

In FIG. 3 the following items are indicated:

9 - metallized surface,

10 is a fragment of a bilateral topological drawing,

11 - metallized micro-holes.

The proposed sequence of regimes when forming a two-sided topological pattern in metallization on substrates with through metallized microholes was chosen, since none of the known methods allows technologically and reproducibly forming a two-sided topological pattern in metallization on substrates with through metallized microholes. In turn, the proposed method allows to solve the technical contradiction between the need for pickling metallization in the formation of a two-sided topological pattern and the inadmissibility of pickling.

This method was practically applied in the formation of the structure of a microwave device based on a waveguide integrated into the substrate. Plates of single-crystal silicon 400 ± 5 μm thick were used as substrates. Through micromachines and thin-film technology, through holes in the diameter of 150 μm were formed in the substrates, after which the substrates and micro holes were metallized using a chromium-copper structure 3-5 μm thick. Substrates were then treated as in FIG. 1 and 2. A positive photoresist FP-RN-7se with a kinematic viscosity of 2.2-2.7 St (mm ² / s) was used as a resist. After dipping the substrate, the resist was dried sequentially in two stages at a temperature equal to half the drying temperature of the resist for at least 4 hours and at a drying temperature of the resist for at least 2 hours. The resist was dried in a SNOL-350 oven. The accuracy of maintaining the temperature was ± 3 ° C.

The results of the practical development of the method are summarized in table 1.

From table 1 it follows that the processing according to the claimed method provides the least defectiveness of the resistive layer and, therefore, manufacturability and reproducibility by improving the quality of products.

After drying, the resist was removed from the metallized surfaces of the substrate by chemical-mechanical treatment with a solvent of the resist, which was used as acetone. Then, resist application was performed using a Sawatec iSpray-300 photoresist application unit. The resist was applied by spreevym on the front side of the substrate at a droplet size of resist _to d << d _{of holes} where _to d - diameter of the resist drops, _holes d - diameter of the through microperforations.

The choice of resist droplet sizes for the spray is illustrated in Table 2.

After applying the resist to the front side, the formed resist layer was dried at a temperature of 100 ° C and the deposition and drying were repeated in the indicated modes for the reverse side of the substrate. Then, two-sided alignment and exposure were carried out, the manifestation of the resist, subduing, etching of the metallization and removal of the resist. The resulting samples are shown in FIG. 3. The absence of metallization etching in microholes was controlled by measuring the ohmic resistance between two surfaces before and after the formation of a two-sided topological pattern in metallization on substrates with through metallized microholes. Both before and after double-sided lithography, the ohmic resistance was less than 0.01 Ohm, which indicates the absence of metallization etching and fully meets the quality criterion of products.

Thus, a technological and reproducible in practice method of forming a two-sided topological pattern in metallization on substrates with through metallized micro-holes has been proposed.

Claims (7)

A method of manufacturing a two-sided topological pattern in the metallization of substrates with metallized micro-holes, comprising the formation of a topological pattern on the metallized surfaces of the substrates, in which the substrate is dipped into a resist followed by first drying and removing the resist and then apply resist spray method on the side of the substrate, followed by final drying, with further exposure, manifestation, downdrafting, etching of the metallization and removal of the resist, characterized in that the first drying of the substrate after dipping into the resist is performed sequentially at a temperature lower than the drying temperature of the resist, and then at the drying temperature of the resist, while spreevym method applied resist on one side of the substrate, followed by final drying of the side of the substrate, and - on the other side of the substrate, followed by final drying of the substrate under the droplet size of the resist applied by spreevym, d << d _{to holes,} where d _k - Diameter drops resist microns, d _holes - the diameter of the through microperforations, um.

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