Proximity effect (electron beam lithography)

About: Proximity effect (electron beam lithography) is a research topic. Over the lifetime, 940 publications have been published within this topic receiving 8508 citations.

A fast electron beam lithography simulator based on the Boltzmann transport equation

Abstract: A fast simulator for electron beam lithography exposure, based on the Boltzmann transport equation is proposed. Using LITHOS (LITHOgraphy Simulator) it is possible to calculate various important parameters which are useful in performing proximity corrections in e-beam lithography and to predict the resist profile after development. This method is proposed as an alternative to the more common Monte Carlo approach as being much faster since it is based on the calculation of analytical expressions. The results obtained by the analytical model are compared to existing experimental results and to those obtained by other methods. The case of a multilayer sample is considered as being of importance in electron beam patterning. All important phenomena (backscattering, secondary electrons) are included in the calculations.

Method of drawing a desired pattern on a target through exposure thereof with an electron beam

Abstract: In a method of drawing a desired pattern on a target through exposure thereof with an electron beam, a pattern area (51, 52) on the target surface is defined by first pixels (53) arranged in rows and columns and is exposed by a first electron beam. A background area (56) other than the pattern area on the target surface is also defined by secondary pixels (58) which are arranged in rows and columns, and is exposed by a secondary electron beam to compensate for the proximity effect. The secondary pixels (58) have a size larger than that of the first pixels (53) and the second electron beam forms on the target surface a second beam spot (59) which is larger than the first beam spot (54) formed on the target surface by the first electron beam so that the background area is exposed in a reduced period of time.

Method of exposing, with correction of pattern data used to draw photomask to overcome proximity effects

Abstract: A correcting method and a correcting apparatus which consider a proximity effect when drawing a pattern of a photomask by an energy beam such as an electron beam or a light proximity effect when performing exposure by using a photomask and obtaining a transfer pattern and can correct the pattern data so that the finally obtained transfer pattern becomes close to the designed pattern even if they occur. Where there is another pattern at the periphery of a pattern in a certain mesh at a center which is subjected to mesh registration, it is decided that a mutual proximity effect will occur at the time of drawing, only a part of the patterns in which it can be considered that the mutual proximity effect will occur are subdivided, and the dosage amount data at drawing are assigned to individual subdivided patterns. Where there is not another pattern at the periphery, it is decided that the self proximity effect will occur at the time of drawing, the peripheral portions of the pattern in which it can be considered that the self proximity effect will occur are subdivided, and the dosage amount data at drawing are assigned to individual subdivided patterns.

Method of correcting pattern data for drawing photomask to overcome proximity effects

Abstract: A correcting method and a correcting apparatus which consider a proximity effect when drawing a pattern of a photomask by an energy beam such as an electron beam or a light proximity effect when performing exposure by using a photomask and obtaining a transfer pattern and can correct the pattern data so that the finally obtained transfer pattern becomes close to the designed pattern even if they occur. Where there is another pattern at the periphery of a pattern in a certain mesh at a center which is subjected to mesh registration, it is decided that a mutual proximity effect will occur at the time of drawing, only a part of the patterns in which it can be considered that the mutual proximity effect will occur are subdivided, and the dosage amount data at drawing are assigned to individual subdivided patterns. Where there is not another pattern at the periphery, it is decided that the self proximity effect will occur at the time of drawing, the peripheral portions of the pattern in which it can be considered that the self proximity effect will occur are subdivided, and the dosage amount data at drawing are assigned to individual subdivided patterns.

Dose modification proximity effect compensation (PEC) technique for electron beam lithography

Abstract: A method of compensating for proximity effects in electron beam lithography systems is disclosed. An uncorrected dose profile is obtained for the pattern features to be introduced into a layer of electron beam sensitive material, including a determination of the clearing dose for the electron beam sensitive resist and the dose height for each edge of the pattern feature. Thereafter the incident dose of exposure energy for introducing an image of the pattern into a layer of electron beam sensitive material is adjusted by designating the clearing dose for each edge of the pattern feature as a function of the dose height. The uncorrected dose profile for determining the dose height and the clearing dose is optionally obtained from a calibration step. Each feature is optionally partitioned into a plurality of subshapes and the incident dose of exposure energy is then adjusted for each edge of each subshape by designating the clearing dose for each edge of each subshape as a function of the dose height.