摘要:
A process for device fabrication is disclosed. In the process, optical lithography is used to introduce an image of a desired pattern into an energy sensitive material. In the process, a filter element is provided. The filter element has at least two regions of different transmittance, each region denominated an aperture. The regions are selected by obtaining information about the desired pattern and an optical lithographic tool that will be used to introduce the image of the desired pattern into the energy sensitive resist material. A filter element that provides an image that, when developed, will provide features with dimensions within acceptable process tolerances is then designed. The filter element is designed by modeling the effects of each aperture of the filter element on the intensity profile of an image of the desired pattern. The combined effect of the apertures is then determined. If required, an aspect (transmittance, orientation, dimension) of the one or more of the proposed apertures is adjusted to provide a modeled intensity profile that more closely corresponds to the desired lithographic result. Once the aspects of all apertures is determined, the filter element is fabricated and used in the optical lithographic process by placing the filter element in the optical lithography tool.
摘要:
An improved attenuated phase-shifting mask (APSM) for use with an imaging tool for forming a patterned feature on a photoresist layer of a semiconductor wafer. The APSM has a transmissive region for substantially transmitting light therethrough to form a projected image substantially shaped as the patterned feature on the photoresist layer. The APSM also has an attenuating and phase-shifting region, contiguous with the transmissive region, for absorbing a portion of the light incident thereon and for shifting the phase of the incident light by a predetermined number of degrees relative to that of the light transmitted through the transmissive region so as to destructively interfere with the light transmitted through the transmissive region and to project a background image. The transmissive region has a dimension d dimensioned such that the intensity of the image projected by the transmissive region is darker than the intensity of the background image projected by the attenuating and phase-shifting region of the mask and that the intensity of the background image is substantially uniform.
摘要:
A lithographic process for making an article such as a semiconductor device or a lithographic mask is disclosed. In the process, articles are fabricated by a sequence of steps in which materials are deposited on a substrate and patterned. These patterned layers are used to form devices on the semiconductor substrate. The desired pattern is formed by introducing an image of a first pattern in a layer of energy sensitive material. The image is then developed to form a first pattern. A layer of energy sensitive material is then formed over the first pattern. An image of a second pattern is then formed in the layer of energy sensitive material formed over the first pattern. The second pattern is then developed. The desired pattern is then developed from the first pattern and the second pattern.