Infineon Technologies Ag

Ernst-Christian Richter

Michael Sebald

Ulrich Scheler

G&uuml;nther Czech

Klaus Elian

Jörg Rottstegge

Gertrud Falk

Stefan Hien

Kerstin Seibold

Siew Siew Yip

Marion Kern

In a process for producing hard masks, an initiator layer that contains an initiator component is applied to a substrate. Then, a photoresist is used to produce a pattern on the initiator layer, in the trenches of which pattern the initiator layer is uncovered. Then, a curable hard mask material is applied and selectively cured, so that only those sections of the hard mask material that adjoin the initiator layer are cured. Finally, uncured hard mask material is removed using a solvent, and at the same time the lands formed from the resist are also removed. The pattern obtained in this way can then be transferred to the substrate, for example using plasma.

Process for producing hard masks

A process for chemically amplifying structured resists includes applying a chemically amplified resist to a substrate and structuring it in a customary manner. Preferably, the amplification agent is applied in an aqueous phase to the structured resist and, after chemical amplification is complete, excess agent is removed by an aqueous wash medium. By using water as a solvent for the amplification agent and as a wash medium, it is possible to avoid organic solvents that constitute an explosion hazard. Furthermore, removal of partially exposed resist sections is suppressed.

Process for modifying resist structures and resist films from the aqueous phase

A method for structuring a photoresist layer is described. A substrate has a photoresist layer containing a film-forming polymer that has a photo acid generator that liberates an acid on exposure to light from a defined wavelength range &#x394;&#x3bb;. In addition, the polymer has a photo base generator that liberates a base on exposure to light from a defined wavelength range &#x394;&#x3bb;. The photoresist layer is first exposed in parts to light from the defined wavelength range &#x394;&#x3bb;, the light being chosen so that the photo base generator is substantially inert to the irradiation. The photoresist layer is then exposed to light from the defined wavelength range &#x394;&#x3bb;, the light being chosen so that the photo acid generator is substantially inert to the irradiation. The photoresist layer is then heated at which the cleavage reaction catalyzed by the photolytically produced acid takes place, and finally the photoresist layer is developed.

Method for structuring a photoresist layer

The method enables determining imaging errors of photomasks for the lithographic structuring of semiconductors. A latent image of the mask is first produced in a photoactivatable layer by exposure. After heat treatment carried out for increasing the contrast and development of the exposed resist, the latter is treated with an amplification agent which preferably diffuses into the exposed parts of the photoresist. There, it reacts with groups of the photoresist, which leads to an increase in the layer thickness of the resist in the exposed parts. A topographical image of the surface of the photoresist, which can be created, for example, by scanning electron microscopy, then indicates imaging errors by protuberances which are located outside the image of the mask. The mask layout can be tested under production conditions and the adjustment and the checking of all components of the phototransfer system used for the production of microchips is facilitated.

Method for experimentally verifying imaging errors in photomasks

A method structures a chemical amplification photoresist layer, in which a photoresist layer of the chemically amplified type is brought into contact, before or after the exposure for structuring, with a base which is capable of diffusing into the photoresist layer. As a result of this treatment with the base, greater steepness and less roughness of the resist profiles are achieved in the subsequent development step.

Method of structuring a photoresist layer

A method for structuring a photoresist layer includes the steps of providing a substrate on which a photoresist layer has been applied at least in some areas. The photoresist layer includes a film-forming polymer that contains molecule groups that can be converted into alkali-soluble groups by acid-catalyzed elimination reactions. The polymer further includes a photoacid generator that, on exposure to light from a defined wavelength range, releases an acid. The polymer additionally has a thermobase generator that releases a base when the temperature is raised. The photoresist layer is initially exposed, in some areas, to light from the defined wavelength range. The photoresist layer is then heated to a temperature at which the elimination reaction catalyzed by the photolytically generated acid takes place and the thermobase generator releases a base. Finally, the photoresist layer is developed.

Process for structuring a photoresist layer

A method for structuring a photoresist layer includes the steps of providing a substrate on which a photoresist layer has been applied at least in some areas. The photoresist layer includes a film-forming polymer that contains molecule groups that can be converted into alkali-soluble groups by acid-catalyzed elimination reactions. The polymer further includes a photobase generator that, on exposure to light from a defined wavelength range, releases a base. The polymer additionally includes a thermoacid generator that releases an acid when the temperature is raised. The photoresist layer is initially exposed, in some areas, to light from the defined wavelength range. The photoresist layer is then heated to a temperature at which the thermoacid generator releases an acid and the acid-catalyzed elimination reaction takes place. Finally, the photoresist layer is developed.

A photoresist layer structuring process includes a substrate with a photoresist layer applied thereto in parts. The photoresist layer includes a film-forming polymer having molecular groups convertable into alkali-soluble groups by acid-catalyzed cleavage reactions. The polymer includes a photoacid generator liberating an acid on exposure to light in a wavelength range, and a photobase generator liberating a base on exposure to light in a wavelength range. First, the photoresist layer is exposed to light from the second range, the light wavelength being chosen so that the photoacid generator is substantially inert to the irradiation, and is exposed to light from the first range, the light wavelength being chosen so that the photobase generator is substantially inert to the irradiation. The photoresist layer is then heated to a temperature at which the cleavage reaction catalyzed by the photolytically produced acid takes place, and finally the photoresist layer is developed.

A method for creating negative resist structures is described. In the method, a chemically fortified resist is applied to a substrate, dried, irradiated with light, x-ray, electron or ion beams, heated, developed using a aqueous-alkaline developer solution and siliconized from a liquid phase. The resist contains the following constituent: a polymer, whose polarity is modified by acidic action and which contains carboxylic acid anhydride groups, preferably in latent form; a compound which releases an acid as a result of thermal treatment; a photoreactive compound, from which a base is created during the irradiation with light, x-ray, electron or ion beams; a solvent; and optionally one or more additives.

Method for producing resist structures

Imaging errors in optical exposure units for the lithographic structuring of semiconductors are determined. First, a latent image of a mask is first produced in a photoactivatable layer by exposure using the optical exposure unit to be tested. After heat treating for increasing the contrast and developing the exposed resist, the latter is treated with an amplification agent which preferably diffuses into the exposed parts of the photoresist. There, it reacts with groups of the photoresist. This leads to an increase in the layer thickness of the resist in the exposed parts. A topographical image of the surface of the photoresist, which can be created, for example, by scanning electron microscopy, then indicates imaging errors by protuberances which are located outside the image of the mask. The method permits testing of optical exposure units under production conditions and thus facilitates the adjustment and the checking of all components of the exposure system used for the production of microchips.

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Erlangen-Bruck, Germany

Ernst-Christian Richter