Wafer holder, heater unit having the wafer holder, and wafer prober having the heater unit

Abstract

A wafer holder less susceptible to deformation even under high load and having high heat-insulating effect and hence capable of improving positional accuracy, improving thermal uniformity and rapid heating and cooling of chips, as well as a heater unit including the wafer holder and a wafer prober including the heater unit are provided. The wafer holder includes a chuck top having a chuck top conductive layer on its surface and a supporter supporting the chuck top, and has a support member in a space between the chuck top and the supporter. Preferably, the support member is arranged concentric with the supporter or approximately at the center of the supporter, and more preferably, support members arranged concentrically and arranged at the center are both provided.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a wafer holder used for a wafer prober in which a semiconductor wafer is mounted on a wafer-mounting surface and a probe card is pressed onto the wafer for inspecting electric characteristics of the wafer, a heater unit including the wafer holder and to a wafer prober including the heater unit. [0003] 2. Description of the Background Art [0004] Conventionally, in the step of inspecting a semiconductor, a semiconductor substrate (wafer) as an object of processing is subjected to heat treatment. Specifically, burn-in is performed in which the wafer is heated to a temperature higher than the temperature of normal use, to accelerate degradation of a possibly defective semiconductor chip and to remove the defective chip, in order to prevent defects after shipment. In the burn-in process, after semiconductor circuits are formed on the semiconductor wafer and before cutting the wafer into i...

AI Technical Summary

Benefits of technology

[0010] The present invention was made to solve the above-described problems. Specifically, an object of the present invention is to provide a wafer holder less susceptible to deformation even under high load and hence capable of effectively preventing contact failure, and having improved heat-insulating effect and hence capable of improving positional accuracy, improving thermal uniformity and rapid heating and cooling of chips, as well as to provide a heater unit including the wafer holder and a wafer prober including the heater unit.

[0021] The heater unit including the wafer prober as described above and the wafer prober including the heater unit have high rigidity and high heat-insulating effect, and therefore, they are capable of improving positional accuracy, improving thermal uniformity and realizing rapid heating and cooling of the chips.

[0022] According to the present invention, in the wafer holder including a chuck top for mounting and fixing a wafer and a supporter supporting the chuck top, a support member is provided in a space between the chuck top and the supporter, and therefore, deflection of the chuck top can significantly be reduced, and hence, a wafer holder less susceptible to deformation even under high load and having improved heat-insulating effect can be provided. According to the present invention, a wafer holder capable of probing even a wafer of large diameter can be provided.

[0023] According to another aspect of the present invention, in the wafer holder including a chuck top for mounting and fixing a wafer and a supporter supporting the chuck top, material of low thermal conductivity having thermal conductivity lower than that of the chuck top is inserted to a space formed between the chuck top and the supporter, and therefore, heat transfer from the heated chuck top to the supporter is suppressed, and the heat-insulating effect can be improved. Thus, a wafer holder can be provided, which can prevent over-heating of the bottom portion of the supporter, prevent increase in temperature of a driving system mounting the wafer holder when a semiconductor wafer having minute circuitry and requiring high accuracy is heated, and prevent over-heating of the facility itself having the heater unit attached thereon.

Problems solved by technology

Therefore, when the chuck top is thin, the chuck top might possibly be deformed, resulting in contact failure between the wafer and a probe pin.

As a result, it takes long time to increase and decrease temperature of the heater, which is a significant drawback in improving the throughput.

As recent chips come to have higher outputs, it is possible that a chip generates considerable heat during measurement of electric characteristics, and in some situations, the chip might be broken by self-heating.

Therefore, when the wafer prober is supported only by the outermost circumference as described in Japanese Patent Laying-Open No. 2001-033484, the prober itself may deform because of the load at the time of probing, uniform contact of the pins of probe card with the wafer would fail and inspection becomes impossible, or in the worst case, the wafer would be broken.

Further, there is a problem that when the wafer is heated to a prescribed temperature, that is, to about 100 to about 200° C., the heat is transferred to the driving system, and metal components forming the driving system thermally expand, degrading positional accuracy.

There is a problem that when the wafer is heated to a prescribed temperature, that is, to about 100 to about 200° C., the heat is transferred to the driving system for moving the wafer holder, and metal components forming the driving system thermally expand, degrading positional accuracy.

Because of such problems, contact failure occurs in inspection of semiconductors having particularly minute circuitry.

Images