Method of testing semiconductor elements and apparatus for testing the same

• US 5,030,908 A
• Filed: 01/23/1990
• Issued: 07/09/1991
• Est. Priority Date: 09/26/1987
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Okumura, Katsuya, Miyoshi, Motosuke
• Primary Examiner(s): Wieder, Kenneth
• Assistant Examiner(s): Burns, William J.
• Application Number:
  US07/468,934
• Time in Patent Office: 532 Days
• Field of Search: 324/158 R, 324/158 D, 324/158 T, 250/310, 250/311
• US Class Current: 324/754.22
• CPC Class Codes: G01R 31/305 using electron beams investigating or analysing materials by measuring photoelectric effect G01N23/227

Abstract

A method and an apparatus for measuring and testing an electric characteristic of a semiconductor device in a non-contact fashion by using an electron beam to induce a voltage on the semiconductor device. By examination of changes with a lapse of time of the induced voltage, the electric characteristics of the semiconductor device are determined.

Claims

1. An apparatus for testing semiconductor elements comprising:

electron beam generator means for radiating an electron beam onto a predetermined target on a semiconductor substrate on which said semiconductor elements are formed,

a grid provided between said electron beam generator means and said semiconductor substrate;

control voltage supply means for supplying a control voltage to said grid in order to control a voltage induced on said target by irradiation by said electron beam,

extraction voltage supply means for supplying an extraction voltage to said grid in order to extract or draw secondary electrons emitted from said target,

switching means for connecting either said control voltage supply means or said extraction voltage supply means to said grid, and

secondary electron detector means for detecting a quantity of secondary electrons from said target which have passed said grid, wherein said control voltage supply means inputs a result detected by said secondary electron detector means as a feedback quantity, to therefore effect control of said grid such that a potential of said target becomes equal to a predetermined value.

3. An apparatus for testing semiconductor elements as set forth in claim 1, wherein said secondary electron detector means comprises a grid for detection, and means for delivering a voltage on basis of said result detected to said grid for detection.

2. An apparatus for testing semiconductor elements comprising:

electron beam generator means for radiating an electron beam onto a predetermined target on a semiconductor substrate on which said semiconductor elements are formed,

a grid provided between said electron beam generator means and said semiconductor substrate,

control voltage supply means for supplying a control voltage to said grid in order to control a voltage induced on said target by irradiation by said electron beam,

extraction voltage supply means for supplying an extraction voltage to said grid in order to extract or draw secondary electrons emitted from said target,

switching means for connecting either said control voltage supply means or said extraction voltage supply means to said grid, and

secondary electron detector means for detecting a quantity of secondary electrons from said target which have passed said grid, wherein said secondary electron detector means comprises an additional grid for detection, and means for delivering a voltage, on the basis of said quantity detected, to said additional grid for detection.

4. An apparatus for non-contact testing of semiconductor elements, comprising:

election beam generator means, operating in a voltage inducing mode and in a measuring mode, for generating an electron beam and directing said electron beam onto a first portion of a predetermined target on a semiconductor substrate on which said semiconductor elements are formed during said voltage inducing mode and for directing said election beam onto a second portion of said target during said measuring mode;

a dual purpose grid located between said electron beam generator means and said semiconductor substrate for acting as a control grid during said voltage inducing mode and as an extraction grid during said measuring mode;

secondary electron detector means for detecting a quantity of secondary electrons from said target, said electrons having passed said grid;

control voltage supply means responsive to said secondary electron detector means, for supplying a control voltage to said grid during said voltage inducing mode for controlling a voltage induced on said target by irradiation of said electron beam;

extraction voltage supply means for supplying an extraction voltage to said grid during said measuring mode for extracting secondary electrons emitted from said target upon irradiation by said electron beam; and

switching means for connecting said control voltage supply means to said grid during said voltage inducing mode and for connecting said extraction voltage supply means to said grid during said measuring mode.