Abstract:
The present invention relates to a multi-beamlet multi-column particle-optical system comprising a plurality of columns which are disposed in an array for simultaneously exposing a substrate, each column having an optical axis and comprising: a beamlet generating arrangement comprising at least one multi-aperture plate for generating a pattern of multiple beamlets of charged particles, and an electrostatic lens arrangement comprising at least one electrode element; the at least one electrode element having an aperture defined by an inner peripheral edge facing the optical axis, the aperture having a center and a predetermined shape in a plane orthogonal to the optical axis; wherein in at least one of the plurality of columns, the predetermined shape of the aperture is a non-circular shape with at least one of a protrusion and an indentation from an ideal circle about the center of the aperture.
Abstract:
For compensation of a magnetic field in an operating region a number of magnetic field sensors (S1, S2) and an arrangement of compensation coils (Hh) surrounding said operating region is used. The magnetic field is measured by at least two sensors (S1, S2) located at different positions outside the operating region, preferably at opposing positions with respect to a symmetry axis of the operating region, generating respective sensor signals (s1, s2), the sensor signals of said sensors are superposed to a feedback signal (ms, fs), which is converted by a controlling means to a driving signal (d1), and the driving signal is used to steer at least one compensation coil (Hh). To further enhance the compensation, the driving signal is also used to derive an additional input signal (cs) for the superposing step to generate the feedback signal (fs).
Abstract:
In a particle-optical projection system (32) a pattern (B) is imaged onto a target (tp) by means of energetic electrically charged particles. The pattern is represented in a patterned beam (pb) of said charged particles emerging from the object plane through at least one cross-over (c); it is imaged into an image (S) with a given size and distortion. To compensate for the Z-deviation of the image (S) position from the actual positioning of the target (tp) (Z denotes an axial coordinate substantially parallel to the optical axis cx), without changing the size of the image (S), the system comprises a position detection means (ZD) for measuring the Z-position of several locations of the target (tp), a control means (33) for calculating modifications (cr) of selected lens parameters of the final particle-optical lens (L2) and controlling said lens parameters according to said modifications.
Abstract translation:在粒子光学投影系统(32)中,通过能量带电粒子将图案(B)成像到目标(tp)上。 所述图案通过至少一个交叉(c)从所述物体平面出射的所述带电粒子的图案化束(pb)中表示; 它被成像为具有给定大小和失真的图像(S)。 为了补偿图像(S)位置与目标的实际定位(tp)(Z表示基本上平行于光轴cx的轴向坐标)的Z偏差,而不改变图像(S)的尺寸, 该系统包括用于测量目标(tp)的若干位置的Z位置的位置检测装置(ZD),用于计算最终粒子光学透镜的选定透镜参数的修改(cr)的控制装置(33) L 2),并根据所述修改来控制所述透镜参数。
Abstract:
In a charged-particle beam exposure device, an electrostatic lens (ML) comprises several (at least three) electrodes with rotational symmetry (EFR, EM, EFN) surrounding a particle beam path; the electrodes are arranged coaxially on a common optical axis representing the center of said particle beam path and are fed different electrostatic potentials through electric supplies. At least a subset of the electrodes (EM) form an electrode column realized as a series of electrodes of substantially equal shape arranged in consecutive order along the optical axis, wherein outer portions of said electrodes (EM) of the electrode column have outer portions (OR) of corresponding opposing surfaces (f1, f2) facing toward the next and previous electrodes, respectively. Preferably, the length of the electrode column is at least 4.1 times (3 times) the inner radius (ri1) of said surfaces (f1, f2).
Abstract:
Apparatus and method for projection ion beam lithography are described which allow formation of low distortion, large field, reduced images of a mask pattern at a wafer plane using an optical column of practical size. The column shown is comprised of an accelerating Einzel lens followed by a gap lens, with numerous cooperating features. By coordinated selection of the parameters of the optical column, lens distortion and chromatic blurring are simultaneously minimized. Real time measurement of the position of the image field with respect to the existing pattern on the wafer is employed before and during the time of exposure of the new field and means are provided to match the new field to the existing pattern even when the latter has been distorted by processing. A metrology system enables convenient calibration and adjustment of the apparatus.
Abstract:
An ion projection lithography system provides an immersion lens between the mask and the substrate, a mask between the immersion lens and the ion source and ExB fiter between the mask and the source but cooperating with a diaphragm located close to the crossing point or focal point of the immersion lens so that ions of undesired mass are rejected from the beam by impingement upon the diaphragm while utilizing low magnetic and electrical field strengths of the ExB filter.
Abstract:
The mask of our invention can be used in image forming units, for example in ion projection microlithography. The mask comprises a mask foil clamped into a retaining frame. The mask foil has a larger thermal expansion coefficient than the retaining frame. To make this mask the mask foil and retaining frame are heatead to a higher temperature than room temperature and clamped in position at this temperature.
Abstract:
Our invention is a process for stabilizing a projection mask which is put in operation at an elevated temperature. The frame containing the mask foil is heated to a temperature which is higher than the temperature of the mask foil. The mask foil is thus kept under tension by controlling the temperature of the frame it is held in and distortions like the distortions which would otherwise occur in long time operation and as conditioned by the mask foil hanging through it are avoided. The effect of the expansion of the mask foil can be compensated in the image forming unit by correction of the image formation scale.
Abstract:
A charged particle system comprises a particle source for generating a beam of charged particles and a particle-optical projection system. The particle-optical projection system comprises a focusing first magnetic lens (403) comprising an outer pole piece (411) having a radial inner end (411′), and an inner pole piece (412) having a lowermost end (412′) disposed closest to the radial inner end of the outer pole piece, a gap being formed by those; a focusing electrostatic lens (450) having at least a first electrode (451) and a second electrode (450) disposed in a region of the gap; and a controller (C) configured to control a focusing power of the first electrostatic lens based on a signal indicative of a distance of a surface of a substrate from a portion of the first magnetic lens disposed closest to the substrate.
Abstract:
The present invention relates to a multi-beamlet multi-column particle-optical system comprising a plurality of columns which are disposed in an array for simultaneously exposing a substrate, each column having an optical axis and comprising: a beamlet generating arrangement comprising at least one multi-aperture plate for generating a pattern of multiple beamlets of charged particles, and an electrostatic lens arrangement comprising at least one electrode element; the at least one electrode element having an aperture defined by an inner peripheral edge facing the optical axis, the aperture having a center and a predetermined shape in a plane orthogonal to the optical axis; wherein in at least one of the plurality of columns, the predetermined shape of the aperture is a non-circular shape with at least one of a protrusion and an indentation from an ideal circle about the center of the aperture.