Abstract: A mask, method of forming the mask, and method of using the mask to form images in a layer of resist layer on an integrated circuit wafer are described. The mask has a first pattern formed in a layer of attenuating phase shifting material. A second pattern formed in a layer of opaque material is formed on the layer of attenuating phase shifting material such that the pattern edges of the first pattern formed in attenuating phase shifting material are exposed, thereby forming a rim type attenuating phase shifting mask. Using this mask to expose a resist layer formed in an integrated circuit wafer achieves the advantages of attenuating phase shifting masks while avoiding problems due to side-lobe effect.

Abstract: This invention describes a new method of forming a double layer attenuating phase shifting mask. A first pattern is formed in a layer of attenuating phase shifting material and an alignment pattern is formed in a layer of opaque material. A first resist is used to form the first pattern. A pellicle is used to restrict the deposition of a second resist to the alignment region of the mask only and as a result neither the first resist nor the second resist must withstand dry etching steps. The first resist is removed before the step of forming the first pattern in the attenuating phase shifting material and cleaning before is step is carried out is thereby improved.

Abstract: A mask and a method of forming a mask having a binary mask pattern in a first region of a transparent mask substrate and a rim type attenuating phase shifting mask pattern in a second region of the same transparent mask substrate. The rim type attenuating phase shifting mask pattern is used to form small contact holes and the binary mask pattern is used to form larger contact holes in an integrated circuit wafer. The use of the rim type attenuating phase shifting mask pattern and the binary mask pattern avoids the problems due to side lobe effect for cases where different size contact holes are required on the same layer in an integrated circuit wafer. The formation of the rim type attenuating phase shifting mask pattern and the binary mask pattern on the same transparent mask substrate increases throughput and decreases cost in the fabrication of integrated circuit wafers.

Abstract: Improvement in the quality of photoresist images has been achieved. The data file in which the full description of the photoresist image, including Optical Proximity Corrections, has been stored is split into two subfiles. The split is made on the basis of separating cell descriptions (where the density of lines is high) from peripheral area descriptions (where lines tend to be isolated). A suitable bias in the form of a small increase or decrease (as appropriate) of all dimensions in the subfile is then applied. After the application of bias, the subfiles are merged back into a single data file and processing proceeds as usual.

Abstract: A method of forming a rim type attenuating phase shifting mask which requires only one resist layer and one resist developing step using a single developing solution. A transparent mask substrate has a layer of attenuating phase shifting material, a layer of opaque material, and a layer of resist material formed thereon. The layer of resist is exposed to a first pattern using a first exposure dose and a second pattern using a second exposure dose. The first exposure dose is sufficient to expose the first pattern in the entire thickness of the layer of resist material. The second exposure dose is sufficient only to expose the second pattern in a top portion of the layer of resist material. The resist is developed and the first pattern is used to etch the first pattern in the layer of opaque material and the layer of attenuating phase shifting material. The resist is then partially etched using an O.sub.2 plasma etch leaving the second pattern in that part of the layer of resist which remains.

Abstract: A mask and method of forming a mask which minimizes the light transmission in the border regions of attenuating phase shifting masks. The mask uses square contact holes formed in the attenuating phase shifting material in the border regions. The square contact holes are located at the edge of the mask pattern region beginning at each corner of the mask pattern region and working toward the center of each side of the mask pattern region using a contact hole pitch. At the center of each side of the mask pattern region the pitch is discontinuous and a row of rectangular contact holes are formed.

Abstract: This invention describes a new method of forming a double layer attenuating phase shifting mask. A first pattern is formed in a layer of attenuating phase shifting material and an alignment pattern is formed in a layer of opaque material. A first resist is used to form the first pattern. A pellicle is used to restrict the deposition of a second resist to the alignment region of the mask only and as a result neither the first resist nor the second resist must withstand dry etching steps. The first resist is removed before the step of forming the first pattern in the attenuating phase shifting material and cleaning before this step is carried out is thereby improved.

Abstract: A new process for fabricating an attenuated phase-shifting photomask is described. A photomask blank is provided comprising a phase-shifting layer overlying a substrate, a chromium layer overlying the phase-shifting layer, and a resist layer overlying the chromium layer. The resist layer of the photomask blank is exposed to electron-beam energy wherein a main pattern area of the photomask blank is exposed to a first dosage of the electron-beam energy and wherein a border area surrounding the main pattern area is not exposed to the electron-beam energy and wherein a secondary pattern area between the main pattern area and the border area is exposed to a second dosage of electron-beam energy wherein the second dosage is lower than the first dosage. The exposed resist layer is developed wherein the resist within the main pattern area is removed to expose the chromium layer. The exposed chromium layer is etched through to expose the underlying phase-shifting layer.