DD225801A1 - POSITIVE PHOTO RESIST - Google Patents

Abstract

The invention relates to a positive photoresist having improved film-forming properties, which is particularly well-suited for use in the fabrication of microelectronic device structures. The object of the invention is the development of a new positive photoresist with improved coating properties and its use in the production of structures especially for microelectronic devices. According to the invention, this is achieved by forming a positive photoresist which is developable after exposure in an alkaline medium and consists of naphthoquinonediazide (1,2) derivatives, polymeric binders, solvents and other additives, a polysiloxane-polyether copolymer compound having a concentration of 0.0001% to 1.0% based on the photoresist is added.

Description

Berlin, April 24, 1982 251/4598/111

inventor

Dr. Lothar Kuhnert Lothar Weh Prof. Hartmut Linde Charlotte Rabe DC Joachim Bernikow DC Wolfgang Baumbach Jürgen Ritter "Reinhard Müller

Positive photoresist

Field of application of the invention

The invention relates to a positive photoresist with improved film-forming properties, which is particularly well suited for use in the fabrication of microelectronic device structures.

Characteristic of the known technical solutions Photosensitive layers, which after exposure have a changed solubility, are used for the production of structures on documents. The layers are usually applied in such a way that a solution of the photosensitive material is applied so that a layer remains after drying and removal of the solvent. The solution of the photosensitive material is called a photoresist. If the exposed image parts are dissolved out by the developer liquid, this is called definitional

12JULi982 * O2i964

according to positive photoresist.

From the various possibilities of producing positive photoresists, it is primarily materials that have been used which, as light-sensitive compounds, contain a uaphthoquinonediazide (1,2) derivative, binder and solvent. By the action of the light, the taphthoquinonediazide derivative is converted to an indenecarboxylic acid which is soluble in alkaline media. After exposure and development leaves a relief image of the unexposed image parts, while exposed in the exposed parts of the image the document is exposed. At the unprotected places a processing of the pad materials can take place. In this way, for example, printing plates can be produced if the substrate is made of aluminum or zinc. In the same photolithographic manner, the production of microstructures for semiconductor devices takes place, being used as underlay materials especially aluminum for conduction paths, vapor-deposited chromium on glass for the production of photomasks and silicon dioxide on silicon for the production of circuits. For the preparation of positive photoresists for the applications mentioned naphthoquinonediazide (1,2) derivatives of various structures and different binders and solvents are used. Thus, according to DE-OS-1 904 764, 2,3,4-trihydroxybenzophenone tris [naphthoquinonediazide (i, 2) -5 * "sulfonate J or 2,4-dihydro 3: ybenzophenone to naphthoquinone [2] diazide-5 As binders, alkali-soluble novolaks and / or other resins containing carboxyl groups, such as cellulose acetate hydrogen phthalate, alkyd resin or polyvinyl hydrogen phthalate, are used in the same specification, and 2-sthoxyethanol is used as the solvent.

Also known are positive photoresists which according to US Pat. No. 4,009,003 contain an esterification product of 2,3,4-trihydroxybenzophenone and naphthoquinones 1,2) -5-sulfonic acid and an m-cresol-formaldehyde resin as binding agent. To improve the performance properties of photoresists other additives such as dyes, photosensitizers, plasticizers or

Adhesion promoters may be added. "As adhesion promoters, organosilicon compounds such as vinylchlorosilane, .alpha.-aminopropyltriethoxysilane or .beta .- (3,4-spycyclohexyl) ethyltrimethoxysilane are often used.

The use of positive photoresists for the production of microelectronic components requires a particularly high quality of the coating properties of the photoresists. Reasons for this are above all:

- Application of projection exposures

- Increasing the diameter of the silicon wafers

- Reduction of the structural geometries.

When using conventional positive photoresists occur in the conventional centrifuge coating for semiconductor materials coating defects such. As strip structures or craters, which is accompanied by a considerable reduction in Biidqualität and thus increasing the reject rate.

Aim of the invention

The object of the invention is the development of a new positive photoresist with improved coating properties and its delivery in the production of structures especially for microelectronic devices.

Object of the invention

It is an object of the present invention to improve the film-forming properties of positive photoresists by using surface-active substances effective in organic media.

Features of the invention

According to the invention, this object is achieved in that a positive photoresist, after exposure in an alkaline. Medium are developable and consists of at least one Naphthochinondiazidd, 2) derivative, polymeric binders, solvents and other additives, a polysiloxane-polyether copolymer compound having a concentration of ο, οοοΐ % to 1.0 %, based on the Photoresist, added.

The polysiloxane-polyether copolymer has the following structure: _r -,

RJ-SiO- [R '-SiOj _ffl -L ^R 2 ^-SiO i n ^-SiH 3: and / or

PE RJ-SiO- [RV-SiO] _m -JRJ-SipJ _a -SiRJ

² and / or

PE

'-Si0] _m -fR • -SiOj - / It' -Sio] _fi -SiRJ

Γι? Sioi ^ 2 I 3

1V | In PE

fR'-Sio) ² I ~ SL

ρε 1

ffo: PE = - (CH ₀ ) O- (OE) - (OP) _n -R " m = 1 to 1 2, preferred".

^ ^{J pq} 2 to 8

OE = -O-CH ₀ -CH ₉ - η = 5 to 250, preferably.

* 10 to 120

OP = -O-CH-CH ₀ - p = 4 to 50

ί ^

CH, q = 4 to 50

R '= alkyl, preferably methyl

R ^lf β aceto, methoxy, butoxy, cyanoethocyl, or urea

(-O-C = O-HHR "*) R ^f " = alkyl or aryl meaning.

Examples of such useful compounds of the invention are:

Compound mn ρ q R ¹ R "R * ' ^f

1 2 5 4 4 Me thyl butoxy methyl ff η 2 6 10 10 15 η 11 phenyl 3 8th 20 10 10 If π η phenyl 4 8th 20 10 10 η Me thozy η 5 6 100 40 40 η butoxy η 6 6 120 50 50 η acetoxy phenyl  7 8th 200 40 40 η Cyanethoxy methyl 8th 10 50 30 30 η --OCONHR * 9 10 10 20 20 τ " Me thoxy 10 12 30 15 15 Me thoxy

Dia compounds according to the invention are distinguished by good compatibility with the customary binders for positive photoresists and improve the layer formation of the photoresists by avoiding streaking and cratering during the coating. The application can be carried out with all commonly used naphthoquinonediazide (1,2) derivatives, binders and solvents. The compounds according to the invention can also be added to commercial positive photoresists which contain further additives for improving the adhesion, photosensitivity or plasticizer and thus improve their performance properties. The application of the new photoresist is particularly advantageous in the production of finest structural geometries in the m-range as they occur in microelectronics components. The application includes all relevant for these purposes ünterlagematerialien such. As aluminum, chromium or silica of various manufacturing methods and can be done both in the production of conductive paths on semiconductor materials as well as in the production of stencils. The use of the compounds according to the invention leads to an improvement in the coating properties of photoresists in all known coating methods such as spray, centrifuge or dip coating.

Embodiment Example 1

A positive photoresist of the following composition is prepared:

10 g of 2,4-dihydroxbenzophenone to naphthoquinonediazide (1,2) -5-sulfonate

22 g of Uovolak resin Alnovol

100 ml of solvent mixture of ethyl glycol acetate and methyl glycol (conveniently in a ratio of 80:20). After dissolving the substances, the solution is filtered in a conventional manner (solution 1) and coated in a coating centrifuge silicon wafers with a diameter of 100 mm at a rotational speed of 8000 U / min. 0.01 % of compounds 1 to are added to the same stock solution and, after coating, the surface finish of the

Photoresist layer assessed.

available Not available rt π It

The results are summarized in Table 1. Table 1: Coating quality

Coating strip structures

ansätζ out

Solution 1

Solution 1 + 0.01 % Compound 1 Solution 1 + 0.02% "5

Solution 1 + 0.02 % ".7

Example 2;

Poaitivfotoresist AZ 1370 H is added to the amounts shown in Table 2 and processed and evaluated under the same conditions as in Example 1.

Table 2; coating quality

Coating approach of strip structures

AZ 1370 H. available

"+ 0.01% Compound 2 not available

Claims (3)

invention claim 1. A process for the preparation of a positive phototez for in particular microelectronic components, characterized in that a positive photoresist is developable after the Beiich »tion in an alkaline medium and from naphthoquinonediazide (1,2) derivatives, polymeric binders, solvents and other additives a polysilazane-polyether copolymer compound having a concentration of 0.0001 % to 1.0 % _t based on the photoresist is added. 2. Positive photoresist according to item 1, characterized in that the polysiloxane-polyether copolymer has the following structure: _{and or} ^ -SiO- [R '-SiOj _m - [H. -SiO] _n -Si-R ₅ PE Ri-SiO Tr "-SiOj. -fR'-Sioi -Si-R ' 3 L, -imL Jn and or R'-SiO-fR'-siol - ["r'-SiO] -Tr'-Sio / -Si-R'3 <- ν m L 2 JnL Jm 3 ^{s τ} ^ ^S 2- ^Si ° Jn PE where: PE = - (CHg) ₃ - (OS) - (0P) -R ^1f m ji 1 to 12, preferably way 2 to 8 way 2 to 8 n = 5 to 25O, preferably 10 to 120 p = 4 to 50 q = 4 to 50 = Alkyl, preferably methyl = Acetoxy, methoxy, butoxy, cyanethoxy or urea (-OCOYYHR ¹ ") OS OP = -O-CH-CH ₂ - R '"= alkyl or aryl meaning.