A wafer probe station is equipped with an integrated environment control enclosure substantially surrounding a supporting surface for holding a test device, such enclosure limiting fluid communication between the interior and exterior of the enclosure and preferably also providing EMI shielding and a dark environment. The limited communication between the interior and exterior of the enclosure is kept substantially constant despite positioning movement of either the supporting surface or probes. The positioning mechanisms for the supporting surface and probes each are located at least partially outside of the enclosure.

Wafer probe station having environment control enclosure

An automatic system for performing sheet resistivity testing on surface layers of semiconductor wafers, including a wafer handling stage having a platform for carrying a semiconductor wafer, and an arrangement for mounting the platform for rotation about a central axis and for translation of the platform orthogonal to a major surface thereof. A platform drive translates the platform between a wafer test position and a wafer load position, and a stage drive rotates the platform to accurately located angular test positions. A probe handling arrangement includes a carriage for carrying a test probe parallel to the major surface of a wafer on the platform and a carriage drive translates the carriage between a parked position in which a test prove thereon is positioned adjacent and clear of the platform and accurately located test positions along a radius of the platform. The carriage carries a resistivity test probe which includes test probe element for contacting the surface of a semiconductor wafer. A light tight housing surrounds the platform and includes an access door therein facing the platform and positioned intermediate the wafer load position and the wafer test position of the platform. The access door translates under controlled motor drive between a closed position and an open position which permits the platform to translate between the wafer load and wafer test positions. Sensor arrangements cooperate with a safety inhibit circuit to preclude destructive movement of components when position conflict is sensed. All movements and measurements are under microcomputer control.

Apparatus and methods for semiconductor wafer testing

Disclosed is a control system and methodology used for defining and executing parametric test sequences using automated test equipment. The control system is divided into components which separate fixed, reusable information from information which is specific to particular tests. One component contains reference data which describes the configuration of the wafer being tested as well as specifications for the tests to be carried out. Another component contains a set of measurement algorithms that describe individual tests to be performed on generic types of devices or parametric test structures. Execution of a test is carried out by a general test program which retrieves stored reference and test definition information and supplies it to the measurement algorithms to enable them to perform measurements on specific devices in the user specified sequence. The general test program additionally routes the measurement results obtained from the algorithms to data files and/or networks, and summarizes the results in a standardized report format.

Control system for automated parametric test equipment

An improved resistivity probe comprised of a rigid strip of electrically nonconducting material having a number of metallic, generally parallel pins coupled thereto. The strip can be mounted in a vertically shiftable probe head in any suitable manner. In one embodiment, the pins are rigidly secured by an epoxy to the strip. In another embodiment, the probe includes a pair of rigid strips having semi-cylindrical recesses on the inner faces thereof for receiving therebetween a number of resistivity measuring pins. The strips are held together by rivets or other fasteners. A multiple probe assembly can be made with a disk-like body having a number of angularly disposed slots therethrough for receiving a number of probes with each probe including a rigid strip having a number of pins coupled thereto. The probes extend into respective slots of the body so that the pins project downwardly from the lower face of the body to permit multiple resistivity measurements to be made without having to rotate the probes. An improved mount for a resistivity probe includes an arm mounted on an upright post for up and down movement, and a moving means which can be electrical, pneumatic, hydraulic or vacuum operated, can be used raising and lowering the arm. A single probe or a multiple probe assembly can be used on the outer end of the arm for making resistivity measurements.

Collinear four-point probe head and mount for resistivity measurements

A device for automatically presenting electronic devices to a tester for testing. A plurality of carriers, each for carrying a set of electronic devices are cyclically conveyed in a close loop from a loading stage where electronic devices are loaded onto the carriers, through a pre-test chamber, such as a "soak" chamber, from the pre-test chamber to a test stage where the devices are preferably lifted from the carrier to come into contact with a test head contactor for testing, from the test stage to a post-test chamber, such as "un-soak" chamber, through the post-test chamber to an unloading stage where the carriers are unloaded of the tested electronic devices, and then from the unloading stage back to the loading stage to receive a new set of untested electronic devices. Optionally, each carrier comprises a set of secondary carriers which ride in a like number of seats defined by a primary carrier and sets of electronic devices are loaded onto and unloaded from the secondary carriers. Among other uses, the secondary carriers serve as adapters between the various forms of electronic devices and a standard form of primary carrier.

Electronic device test handler

Disclosed is a method and apparatus to improve the capabilities of automatic and semi-automatic diode, integrated chip, and wafer probers Prober contact with the upper surface of the wafer to be tested is accomplished through an electronic logic circuit triggered by electrical contact of the probe as opposed to a mechanical sensor This improved surface position signal is supplied to additional digital logic circuitry to operate a vertical axis control mechanism which precisely locates the probes relative to the wafers that will be tested Thus, prober contacts with test wafers are positively and accurately made improving the reliability of the test stage of wafer production

Apparatus for wafer probing having surface level sensing

A method is described which allows quantitative lines of a spark source mass spectrum on a photographic plate to be represented by three parameters only. These three parameters are the maximum absorption of the line, background, and the area produced by an integrator when the line is scanned on a microdensitometer. From these three data, plus the measured response characteristics of the photographic plate, a mathematical technique is described which yields the total number of ions which produced the line. A digital computer program is used in carrying out the mathematical method. The only assumption made is that the intensity of the beam which produced the line followed a normal (Gaussian) distribution about the point of maximum darkening.

Lewis A. Fergason

Papers

Apparatus for wafer probing having surface level sensing

Determination of Ion Intensities from Spark Source Mass Spectrometry Photoplates