公开(公告)号：US4864228A

公开(公告)日：1989-09-05

申请号：US766905

申请日：1985-08-16

Applicant: Neil Richardson

Inventor： Neil Richardson

IPC: G01Q60/30 ,  G01R31/305 ,  H01J37/26

CPC classification number: H01J37/268 ,  G01R31/305

Abstract: An improved electron beam test probe apparatus and a method for use of said apparatus for use in measuring the potential in a specimen which enables measurements to be insensitive to local electric fields in the vicinity of the point at which the potential of the specimen is being measured. The apparatus consists of an electron beam for bombarding the specimen at the point at which the potential of the specimen is to be measured, a magnetic lens for collimating the secondary electrons emitted fom the specimen in response to this bombardment, and a detector system for measuring the energy distribution of the secondary electrons so collimated. Tubular electrodes are employed in the energy distribution detection system. These electrodes have significantly higher field uniformity and intercept a smaller fraction of the secondary electrons than wire mesh electrodes. The electrodes are supported on insulators constructed from slightly conductive plastic which prevent the buildup of static charges which can lead to unpredictable fields. The electron beam used to bombard the specimen is of a substantially lower energy than that used in scanning electron microscopes, thus reducing the problems associated with the high energy electron beam bombardment. Improved electronic delay circuitry which employs a tandem combination of a digital delay technique and an analog delay technique has been developed to allow the electron beam to be turned on in short pulses in precise time synchrony with test signal patterns applied to a circuit being tested. This delay circuitry allows the timing of these short pulses to be specified to an accuracy of 5 picoseconds relative to a trigger pulse which is applied to the delay circuitry several milliseconds earlier. An improved signal averaging circuit has been developed which improves the signal to noise ratio and response time.The apparatus may be used to produce an image of the specimen in the vicinity of the point under bombardment while measuring the potential at said point. The methods taught by the present invention allow the measurement or the potential on buried conductors located beneath an insulating layer. The methods taught also prevent drift in the electron beam resulting from varying surface electric fields on the specimen.

公开(公告)号：US4721909A

公开(公告)日：1988-01-26

申请号：US828157

申请日：1986-02-10

Applicant: Neil Richardson

Inventor： Neil Richardson

IPC: G01R31/305 ,  H01J37/04 ,  H01J37/26 ,  H01J37/147

CPC classification number: G01R31/305 ,  H01J37/045 ,  H01J37/268

Abstract: An apparatus for pulsing an electron beam in an electron beam test probe used for examining integrated circuits is disclosed. The apparatus includes a structure having two intersecting channels cut therein. The electron beam passes through a first one of these channels enroute to the integrated circuit being tested. A linear conductor is disposed along the axis of the second channel such that the combination of said conductor and said second channel forms a coaxial transmission line. An electric field is generated in the second channel by applying a suitable potential between the linear conductor and the second channel. This electric field extends into the first channel from the region common to both channels. When a suitable potential is applied between the linear conductor and the second channel, the electric field generated deflects the electrons traveling in the first channel sufficiently to cause said electrons to miss an aperture through which said electrons must pass to reach the circuit being analyzed.

Abstract translation: 公开了一种用于在用于检查集成电路的电子束测试探针中脉冲电子束的装置。 该装置包括其中切割有两个相交通道的结构。 电子束通过这些通道中的第一个通道到被测试的集成电路。 沿着第二通道的轴线设置线性导体，使得所述导体和所述第二通道的组合形成同轴传输线。 通过在线性导体和第二通道之间施加合适的电位，在第二通道中产生电场。 该电场从两个通道共同的区域延伸到第一通道中。 当在线性导体和第二通道之间施加合适的电位时，产生的电场使得在第一通道中行进的电子足够地偏转，使得所述电子错过所述电子必须通过的孔以到达被分析的电路。