CS269152B1 - Method of photoresist layers' surface treatment,applicated on semiconductor plate - Google Patents

Abstract

ieSení relates to a method of surface treatment photoresist layers deposited on semiconductor dasoa when dry etching in a fluorinated atmosphere hydrocarbons, followed by wet etching and rinsing the surface. The essence of the solved The problem is that after dry etching, the semiconductor plate is subjected to plasma argon physical bombardment in an electric field accelerated argon ions. Surface treatment method Photoresist Layers of Flesh to Use in Field · processing and manufacturing of semiconductor devices and brings the benefits of a reliable and fully re-reproducible thin removal superficial, fluorine-saturated surfaces fotorssistové spindle, so it does not deteriorate adhesion of other layers applied on the substrate surface in the semiconductor holes desos, which results in higher recovery of faultless chips on semiconductor compared to the current state techniques

Description

The invention relates to a method for treating the surface of photoresist layers deposited on a semiconductor board in cases where dry etching of the surface in an atmosphere containing fluorocarbons is followed by wet etching and rinsing.

Various technologies for processing semiconductor components and integrated circuits are currently known. Their basis is often the shaping of thin layers of dielectric materials, metals or even the semiconductor material itself using a light-sensitive varnish, the so-called photoresist. Two methods are usually used to shape thin layers. The first method consists in etching the layers in the photoresist mask, the second method consists in applying a thin layer on the photoresist mask and the following: washing away the applied thin layer with the photoresist, where the applied thin layer said thin layer holes in the photoresist. The second method is sometimes carried out by first etching the underlying layer over the photoresist mask and only then, as already mentioned, applying another, mostly metallic, thin layer, followed by the already mentioned washing of the top layer with the photoresist. For etching layers through photoresist masks, according to the just mentioned modification of the second method, either wet processes with solutions of acids, bases or their salts are used, or dry processes, so-called dry etching, are used, and sometimes a combination of both processes is used. Dry etching is performed in a low-temperature reactive gas plasma generated by a high-frequency log with random movement of particles in the flowing gas or with acceleration of the particles by an electric field. Dry etching takes place in an atmosphere of a mixture of fluorocarbons and oxygen or only in an atmosphere of fluorocarbons. This atmosphere causes changes on the surface of the photoresist mask. A thin surface layer saturated with fluorine is formed, which changes the original C-H bonds to C-H bonds. If wet etching is applied after dry etching, a thin fluorine-doped surface layer is torn off from the surface of the photoresist mask after the previous dry etching. Torn pieces of thin surface. the fluorine-saturated layers are not perfectly washed away or indicated during visual inspection, because they are difficult to see even under a microscope and cause imperfect adhesion of subsequently applied, e.g. metal layers, on the surface of the substrate in the openings of the photoresist mask. In these places, after the metal with the photoresist layer is washed away, the metal motif is torn off even in the place where it should have been preserved. If, after dry etching, we expose a semiconductor plate with a photoresist mask, either in the plasma of oxygen or nitrogen or successively in the plasma of both gases, which is a purely chemical etching method, the thin, fluorine-saturated photoresist layer and its residues are not reliably or reproducibly removed. they cause, as in the previous case, imperfect adhesion of the subsequently applied layers, which results in a reduction in the yield of chips on the semiconductor board. The probable cause of the uncertain reproducibility of the process is the unequal composition of the thin, fluorine-saturated photoresist layer in the individual batches.

These disadvantages are eliminated by the method of surface treatment of photoresist layers deposited on a semiconductor board according to the invention, the essence of which consists in that after dry etching the semiconductor board with photoresist layer is subjected to physical action in argon plasma by bombardment in electric field by accelerated argon ions.

This method of treating photoresist layers offers the advantages of reliable and fully reproducible removal of a thin, surface, fluorine-saturated layer from the photoresist mask surface, so the adhesion of other layers deposited on the substrate surface in the photoresist mask holes is not impaired. '

In the accompanying drawing, FIGS. 1 to 5 show semiconductor boards with applied layers, successively treated.

Fig. 1 shows a semiconductor board 1, a dielectric layer 6 and a photoresist layer J, in which an upper hole 2 is formed.

Fig. 2 shows the state of Fig. 1 after dry etching of a part of the dielectric layer 2

CS 269 152 B1 vy 2. below the rocks through the opening 1 and e formed by a thin, fluorine-saturated surface layer £ on the photoresist mask

Fig. 3 shows the state of Fig. 2 after removing the thin, fluorine-saturated surface layer 6 and after wet etching with an etched bottom hole ^{1 in the} semiconductor board 1.

Fig. 4 shows the state of Fig. 3 with a metal layer applied

Fig. 5 shows the state of Fig. 4 after dissolution of the photoresist layer 6 and its washing away at the same time as a part of the metal layer 6 deposited thereon.

An example of a method of treating the surface of photoresist layers deposited on a semiconductor board is the following procedure for forming a Ti-Pt-Au metal layer for a MESFET gate by etching through a dielectric layer and a photoreslet mask. A dielectric layer 6 is applied to the semiconductor plate X, to which a photoresist layer 1 is applied, in which the upper opening 2 is opened using some known lithographic technology. Dry etching of the dielectric layer 2 follows, forming a thin , fluorine-saturated surface layer £. This is then removed by subjecting it, in an argon plasma, to physical action by electric field bombardment with accelerated argon ions, which can be carried out in the same apparatus if a physico-chemical dry etching method has been used, or in a different apparatus regardless of the previous one; dry etching method. Removal of the thin, fluorine-saturated layer E is followed by wet etching, in which the bottom hole 2 is etched in the semiconductor board 1 and then a metal layer is applied in a vacuum by immersing the semiconductor board χ and layers 2, J and 6 in a common solvent & sonicated by an ultrasonic field. the photoresist layer £ is dissolved and washed away, and thus the metal layer £ is washed away at the places where it was applied to the photoresist layer 2. In the place of the lower hole 2, the metal layer £ remains in the formed shape.

The method of surface treatment of photoresist layers according to the invention can be used in the field of semiconductor device manufacturing where it is necessary to remove a thin, fluorine-saturated layer from the surface of the photoresist mask.

Claims (1)

'' SUBJECT V I X 1 L S Z U Method for surface treatment of photoresist layers deposited on a semiconductor board subjected to dry etching in an atmosphere containing fluorocarbons, followed by wet etching, characterized in that after dry etching, the semiconductor board (1) with photoresist layer (3) is subjected in plasma argon by physical action by bombardment in an electric field by accelerated argon ions.