摘要:
An electron beam system for direct writing applications combining the parallel throughput of a projection system and the stitching capability of a probe-forming system employs an electron gun to illuminate an initial aperture uniformly, a first set of controllable deflectors to scan the beam over the reticle parallel to the system axis, impressing the pattern of a subfield of the reticle in each exposure, in which a first variable axis lens focuses an image of the initial aperture on the reticle, a second variable axis lens collimates the patterned beam, a second set of controllable deflectors to bring the beam back to an appropriate position above the wafer, and a third variable axis lens to focus an image of the reticle subfield on the wafer, together with correction elements to apply aberration corrections that may vary with each subfield, thereby providing high throughput from the use of parallel processing of the order of 10 7 pixels per subfield with the low aberration feature of the variable axis lens and the ability to tailor location-dependent corrections that are associated with gaussian systems that stitch the image pixel by pixel.
摘要:
Zum Korrigieren der Ausrichtung eines Elektronenstrah les, mit dem eine Auftreffplatte (12) beaufschlagt wird, wird die Strahlquelle (10) elektronenoptisch auf eine zentrale, kreisförmige Öffnung (27; Fig. 4) einer Ausblendplatte (28) abgebildet. Zu ausgewählten Zeiten wird das Bild der Strahlquelle auf eine zweite kreisförmige Öffnung (35) in der Ausblendplatte abgelenkt. Mittels eines Ablenk-Joches (30) erfolgt ein genaues Ausrichten des Bildes der Strahlquelle auf diese zweite Öffnung. Deren Durchmesser entspricht etwa der Halbwertsbreite W der Stromdichteverteilung des Bildes der Strahlquelle in dieser Öffnung. Das genaue Ausrichten des Bildes der Strahlquelle auf die zweite Öff nung erfolgt durch kleine Verschiebungen des Bildes. Diese werden beendet, wenn der die zweite Öffnung durchfließen de Elektronenstrom einen Maximalwert annimmt. Dann wird der Elektronenstrahl wieder zu der zentralen kreisförmigen Öffnung der Ablenkplatte gelenkt. Deren Durchmesser beträgt mindestens etwa das doppelte der Halbwertsbreite W der Stromdichteverteilung des Bildes der Strahlquelle in dieser Öffnung. Dadurch bleiben die zur Ausrichtung des Elektronenstrahles vorgenommenen Verschiebungen des Bildes der Strahlquelle ohne merklichen Einfluß auf den die zentrale Öffnung durchfließenden Elektronenstrom, der zur Auftreffplatte gelangt.
摘要:
The system tests the continuity of electrical conductors extending through an insulating layer without contact. A flood gun (11) irradiates one side of the body (18) to charge the exposed conductors to a given potential. A steerable electron beam (14) scans the front side to generate secondary electron emission from those conductors, which secondary emission is measured by a detector (24). The secondary emission is enhanced from conductors with conductivity between front side and back side as a result of the surface potential established by the rear flood beam (22). The secondary emission varies depending on the state of continuity in the three-dimensional network of conductors and produces signals at the detector (24) which allow clear discrimination between uninterrupted and interrupted conductors. The system is applicable for unfired ceramics where contact destroys the specimen.
摘要:
A two stage, electron beam projection system includes a target, a source of an electron beam and means for projecting an electron beam towards the target with its upper surface defining a target plane. A magnetic projection lens has a principal plane and a back focal plane located between said means for projecting and the target. The means for projecting provides an electron beam directed towards the target. First stage means provides deflection of the beam from area to area within a field. Second stage means provides for deflection of the beam for providing deflection of the beam within an area within a field. The beam crossing the back focal plane produces a telecentric condition of the beam in the image plane with the beam substantially normal to tghe target plane from the principal plane to the target plane. The magnetic projection lens includes a magnetic structure providing for magnetic compensation positioned within the bore of the projection lens, which produces a compensating magnetic field substantially proportional to the first derivative of the axial magnetic projection field. The axial magnetic projection field provides substantially a zero first derivative of the axial magnetic projection field in the vicinity of the target. The projection system projects on the target plane from the projection system as deflected by the upper and lower stages, at all times maintaining the telecentric condition of the electron beam at the target plane throughout the entire range of deflection of the beam, assuring minimum errors due to target height variations.
摘要:
An electron beam system for direct writing applications combining the parallel throughput of a projection system and the stitching capability of a probe-forming system employs an electron gun to illuminate an initial aperture uniformly, a first set of controllable deflectors to scan the beam over the reticle parallel to the system axis, impressing the pattern of a subfield of the reticle in each exposure, in which a first variable axis lens focuses an image of the initial aperture on the reticle, a second variable axis lens collimates the patterned beam, a second set of controllable deflectors to bring the beam back to an appropriate position above the wafer, and a third variable axis lens to focus an image of the reticle subfield on the wafer, together with correction elements to apply aberration corrections that may vary with each subfield, thereby providing high throughput from the use of parallel processing of the order of 10 7 pixels per subfield with the low aberration feature of the variable axis lens and the ability to tailor location-dependent corrections that are associated with gaussian systems that stitch the image pixel by pixel.
摘要:
A two stage, electron beam projection system includes a target, a source of an electron beam and means for projecting an electron beam towards the target with its upper surface defining a target plane. A magnetic projection lens has a principal plane and a back focal plane located between said means for projecting and the target. The means for projecting provides an electron beam directed towards the target. First stage means provides deflection of the beam from area to area within a field. Second stage means provides for deflection of the beam for providing deflection of the beam within an area within a field. The beam crossing the back focal plane produces a telecentric condition of the beam in the image plane with the beam substantially normal to tghe target plane from the principal plane to the target plane. The magnetic projection lens includes a magnetic structure providing for magnetic compensation positioned within the bore of the projection lens, which produces a compensating magnetic field substantially proportional to the first derivative of the axial magnetic projection field. The axial magnetic projection field provides substantially a zero first derivative of the axial magnetic projection field in the vicinity of the target. The projection system projects on the target plane from the projection system as deflected by the upper and lower stages, at all times maintaining the telecentric condition of the electron beam at the target plane throughout the entire range of deflection of the beam, assuring minimum errors due to target height variations.