JP2001007164A - Prober - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid oxidation and condensation by keeping the surfaces of a sample in a high-concentration purge gas atmosphere. SOLUTION: This prober tests the characteristics of a semiconductor wafer, etc., in a purge gas atmosphere. To keep the surfaces of a wafer in a high- concentration purge gas atmosphere, this prober is equipped with a nitrogen purge nozzle 31 which blows purge gas on the surfaces of a wafer, and a purge box 2 which forms a stationary state where the wafer is entirely enclosed with a high-concentration purge gas atmosphere and the concentration decreases with distance from the sample surfaces. An XYθZ stage 23 has an air bearing to which purge gas is supplied. The purge box 2 consists of a shield case 5, in which a prober 1 is contained, and a pass box 6 adjusted to the concentration same as that in the shield case 5, through which a wafer is loaded or unloaded. The internal pressure of the shield case 5 is made higher than that of the pass box 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prober used for performing a characteristic test of a plate-like sample having a circuit or the like formed on a surface thereof, such as an IC wafer or a liquid crystal plate, and more particularly, to purging a part to be tested with a purge gas. It relates to a prober that performs a test in an atmosphere.

[0002]

2. Description of the Related Art When performing a characteristic test of a sample having a circuit formed on a surface, heating and cooling are performed in various environments. In this case, the test is performed in a purge gas atmosphere to prevent oxidation at a high temperature and dew condensation at a low temperature.

For this reason, the prober is stored in a purge box. A purge gas supply device for supplying a purge gas into the purge box is connected to the purge box.

Accordingly, the purge gas is filled in the purge box by the purge gas supply device until the purge gas has a constant concentration, and a circuit characteristic test is performed in a purge gas atmosphere having a constant concentration.

[0005]

However, in the prober having the above structure, if the purge gas in the purge box is not uniform or there is an air flow, the surface of the sample cannot be maintained in a high-concentration purge gas atmosphere.

[0006] If the surface of the sample is not maintained in a high-concentration purge gas atmosphere, there is a problem that the surface of the sample is oxidized or dewed.

The present invention has been made in view of the above problems, and has as its object to provide a prober that can maintain the surface of a sample in a high-concentration purge gas atmosphere at all times during a test.

[0008]

According to a first aspect of the present invention, there is provided a prober for testing the characteristics of a sample having a circuit or the like on a surface thereof in a purge gas atmosphere. A purge gas supply system that blows a purge gas directly onto the surface of the sample to cover the sample at least, and the entire surface of the sample is in a high-concentration purge gas atmosphere. And a purge box for forming a state.

[0009] With the above structure, the purge gas is directly blown from the purge gas supply system to the surface of the sample.
The surface of the sample becomes a high concentration purge gas atmosphere. The concentration of the purge gas gradually decreases while spreading from the surface of the sample to the periphery. The surrounding purge gas fills the purge box, and the purge box is maintained at a low-concentration purge gas atmosphere. Thereby, a steady state is maintained. That is, the surface of the sample, which is the central portion, is maintained in a high-concentration purge gas atmosphere, and the gas concentration decreases with increasing distance from the central portion, and is maintained in a steady state where there is no change in the concentration at a fixed position.

A prober according to a second aspect of the present invention is the prober according to the first aspect, wherein an air bearing is provided on the mounting table for mounting the sample, and the mounting table is accommodated in the purge box. The purge gas is used as the supplied gas, and the purge gas is supplied into the purge box.

According to the above configuration, the purge gas is supplied into the purge box by using the air bearing. As a result, the purge gas is filled in the purge box, the periphery of the sample is covered with the low-concentration purge gas atmosphere, and the steady state is maintained.

A prober according to a third aspect of the present invention is the prober according to the first or second aspect, wherein the purge box houses the entire apparatus and forms the steady state, and the purge box is connected to the shield case. And a pass box for adjusting the purge gas concentration to the concentration in the shield case and taking the sample in and out of the shield case. .

According to the above configuration, the inside of the shield case of the purge box is maintained in the steady state. When the sample is placed in the shield case in this state, the space between the shield case and the pass box is shut off, the opening / closing door is opened, and the sample is placed in the pass box. Next, the door is closed, and the purge gas concentration is adjusted to the same concentration as in the shield case. Next, the shield case and the pass box are communicated with each other, and a test is performed by placing the sample on a mounting table in the shield case. The removal of the sample is performed in a process reverse to that described above.

A prober according to a fourth aspect of the present invention is the prober according to the third aspect, wherein the internal pressure of the shield case of the purge box is higher than the internal pressure of the pass box.

In the above configuration, for example, the internal pressure of the shield case of the purge box is set slightly higher than the internal pressure of the pass box. Thus, when the shield case and the pass box are communicated with each other, a state in which the gas in the shield case slightly flows toward the pass box is formed. When a sample is exchanged between the shield case and the pass box in this state, the purge gas atmosphere in the shield case is not stirred so much, and the surface of the sample can be maintained in a high-concentration purge gas atmosphere.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a prober according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic front view showing a state where the prober according to the present embodiment is housed in a purge box, FIG. 2 is a perspective view showing a state where the prober according to the embodiment is housed in a purge box, and FIG. FIG. 4 is a front view showing the prober according to the embodiment, FIG. 4 is a plan view showing the prober according to the present embodiment, and FIG. 5 is a side view showing the prober according to the present embodiment.

The prober 1 is housed in a purge box 2 as shown in FIGS.

The purge box 2 is a box for keeping the prober 1 in a purge gas atmosphere, and includes a shield case 5 and a pass box 6.

The shield case 5 is a case for housing the prober 1 to form a sealed space. The shield case 5 is formed in a substantially cubic shape, and an inclined window 7 is provided on the front surface thereof. Glass is attached to the window 7 so that the inside can be observed. Further, an inner working glove 8 is provided at a lower portion of the front surface of the shield case 5. The worker inserts both hands into the shield case 5 through the internal work glove 8 to perform work. An open valve 9 is provided on the upper side surface of the shield case 5. The opening valve 9 allows only one gas flow. That is, the outflow of the gas in the shield case 5 to the outside is allowed, and the inflow of the outside gas into the inside is prevented. Further, the opening valve 9 has a pressure adjusting function so that the pressure in the shield case 5 can be maintained at a set value. A pressure gauge 10 for checking the pressure in the shield case 5 is provided beside the opening valve 9. A purge gas supply device (not shown) for supplying nitrogen gas (dry nitrogen gas containing no moisture) as a purge gas is connected to the inside of the shield case 5 via a pipe H.

The pass box 6 is a box for taking samples in and out. Here, since the characteristic test of the semiconductor wafer S is performed, the wafer cassette 11 supporting a plurality of semiconductor wafers S is put in and out of the pass box 6. The pass box 6 is attached to one side (the right side in FIG. 1) of the shield case 5. The pass box 6 has its left side open and communicates with the shield case 5. An internal door 13 is provided at a communication port 12 which is a boundary between the pass box 6 and the shield case 5. The inner door 13 is formed of a flat plate, and its upper and lower sides are supported by support rails 14 and 15. Thereby, the inner door 13 slides back and forth, and opens and closes the communication port 12. The pass box 6 includes the wafer cassette 11
It is formed to have a size slightly larger than that. An opening / closing door 16 is attached to one side of the pass box 6.
By opening the door 16, the wafer cassette 11 can be taken in and out of the pass box 6. Further, in the pass box 6, a pressure gauge 18, a purge gas supply device (not shown), and a vacuum pump (not shown) are connected. Thereby, after the wafer cassette 11 is inserted into the pass box 6 from the outside, the inside of the pass box 6 is evacuated by the vacuum pump, and then the purge gas is injected, so that the inside of the pass box 6 is almost equal to the inside of the shield case 5. At a similar concentration, it is adjusted to a slightly lower pressure purge gas atmosphere.

The prober 1 is configured as shown in FIGS. 1, 3 to 5. In FIG. 1, a prober 1 is schematically illustrated to facilitate understanding of the features of the present invention. For this reason, the prober 1 of FIG. 1 and the prober 1 of FIGS. 3 to 5 have some differences in the configuration, but have essentially the same configuration.

The prober 1 mainly includes a base 22 and XYθ
Z stage 23, hot chuck 24, purge plate 2
5, a base plate 26, a probe 27, a manipulator 28, and a microscope 29.

The base 22 is a base that supports the XYθZ stage 23 and the like. The XYθZ stage 23 is installed on the base 22 while being supported by the guide rail 30. The XYθZ stage 23 supports a hot chuck 24 as a mounting table on which a sample is mounted.
Fine adjustment in the θZ direction.

The hot chuck 24 is a portion on which the test sample is directly placed, and heats or cools the placed sample according to the test conditions. For this reason, heating means and cooling means are incorporated in the hot chuck 24. This hot chuck 24 is fixed to the upper surface of the XYθZ stage 23. The XYθZ stage 23 moves and rotates the hot chuck 24 in the front-rear, left-right and up-down directions, and accurately aligns the sample with the tip of the probe 27. A fixed space is maintained between the hot chuck 24 and the purge plate 25 to form a purge space. This purge space forms a high concentration purge gas atmosphere. This high-concentration purge gas atmosphere prevents the surface of the test sample from being oxidized at a high temperature or dewed at a low temperature.

A nitrogen purge nozzle 31 (see FIG. 1) is provided above the hot chuck 24. The nitrogen purge nozzle 31 is provided facing the purge space, and blows a nitrogen gas as a purge gas into the purge space. The nitrogen purge nozzle 31 is connected to a purge gas supply device (not shown). The amount of the purge gas blown from the nitrogen purge nozzle 31 is set to such an extent that the periphery of the purge space is maintained in a steady state.
That is, the purge space at the center is maintained in a high-concentration purge gas atmosphere, the gas concentration decreases as the distance from the purge space increases, and the gas concentration is set to such a level that the concentration does not change at a fixed position in a steady state. You.

On the mounting surface (upper surface) of the hot chuck 24, a suction port (not shown) connected to an external vacuum device (not shown) is provided to suck the mounted sample. To support.

The purge plate 25 is attached to the lower side of the base plate 26 so as to face the hot chuck 24. Thus, the purge space is formed by the mounting surface of the hot chuck 24 and the purge plate 25. At the approximate center of the purge plate 25, a probe insertion hole 25A for inserting the probe 27 and the nitrogen purge nozzle 31 toward the sample is provided.

The probe 27 is supported by a manipulator 28. The manipulator 28 is mounted on the base plate 26 while supporting the probe 27. The manipulator 28 has a built-in magnet (not shown) so that it can be fixed at an arbitrary position on the base plate 26.

The XYθZ stage 23 incorporates an air bearing mechanism (not shown). The XYθZ stage 23 can freely move on the base 22 while being supported by the guide rail 30 by this air bearing mechanism.

[Operation] In the prober 1 configured as described above, a circuit characteristic test of a sample is performed as follows.

A purge gas is supplied from a purge gas supply device into the shield case 5 of the purge box 2 to make the inside of the shield case 5 a low-concentration purge gas atmosphere. At this time, the inside of the shield case 5 is adjusted to a pressure slightly higher than the atmospheric pressure by the opening valve 9. Further, a purge gas is supplied from a nitrogen purge nozzle 31 to a purge space on the upper side surface of the hot chuck 24 to maintain a high-concentration purge gas atmosphere. At this time, the purge gas blown out from the nitrogen purge nozzle 31 gradually becomes a low-concentration purge gas while spreading from the purge space to the surroundings, and changes to the concentration of the purge gas atmosphere in the shield case 5. In this concentration change, the low-concentration purge gas atmosphere in the shield case 5 functions as a buffer, preventing a sharp decrease in concentration. That is, the concentration is not suddenly reduced from the high concentration purge gas in the purge space to the purge gas concentration of 0%, but is buffered by the low concentration purge gas atmosphere in the shield case 5. As a result, the atmosphere in the purge space changes stably from the high-concentration purge gas atmosphere to the surrounding low-concentration purge gas atmosphere, and the steady state is maintained.

The inner door 13 is closed, and the shield case 5 and the pass box 6 are shut off. In this state, the open / close door 16 of the pass box 6 is opened, the wafer cassette 11 containing a plurality of semiconductor wafers S as samples is inserted into the pass box 6, and the open / close door 16 is closed. Next, the inside of the pass box 6 is evacuated by a vacuum pump to remove some of the air therein. Next, a purge gas is supplied from the purge gas supply device and is filled in the pass box 6. In the evacuation and the supply of the purge gas, the concentration of the purge gas in the pass box 6 is adjusted to be substantially equal to the concentration of the purge gas in the shield case 5. The pressure inside the pass box 6 is adjusted by the pressure gauges 10 and 18 so as to be slightly lower than the pressure inside the shield case 5.

In this state, the operator inserts both hands into the shield case 5 through the internal work glove 8 and opens the inner door 13 to allow the shield case 5 and the pass box 6 to communicate with each other. Then, one semiconductor wafer S is taken out from the wafer cassette 11 and placed on the hot chuck 24. If there is a semiconductor wafer S already inspected in the hot chuck 24, it is stored in the wafer cassette 11 in place of a new semiconductor wafer S. Thereafter, the inner door 13 is closed. At this time, since the internal pressure of the pass box 6 is lower than that of the shield case 5, a situation in which the purge gas in the shield case 5 slightly flows into the pass box 6 is formed, and the purge gas atmosphere in the shield case 5 is scratched. It will not be disturbed.

Next, the XYθZ stage 23 is roughly adjusted in position while operating the air bearing. Next, while finely adjusting the hot chuck 24 with the XYθZ stage 23, a predetermined position of the semiconductor wafer S is aligned with the tip of the probe 27, and a circuit characteristic test is performed. At this time, since the purge space is in a high-concentration purge gas atmosphere, even if the semiconductor wafer S is heated or cooled,
The surface of the semiconductor wafer S is not oxidized or dewed.

When the air bearing is operated, the purge gas is supplied into the shield case 5 and the purge gas is supplied.
To be charged within. Further, the purge gas of the nitrogen purge nozzle 31 is also filled in the pass box 6. As a result, the purge gas concentration in the shield case 5 gradually increases, but at the same time, the pressure also increases, so that the purge gas escapes from the opening valve 9 and also to the pass box 6 and stays at a certain concentration.

When the circuit characteristic test is completed for all the semiconductor wafers S, the internal door 13 is closed, the opening / closing door 16 is opened, and the wafer cassette 11 is taken out.

[Effect] As described above, the hot chuck 2
4 is maintained in the above-mentioned steady state, and the hot chuck 24 is maintained.
Since the purge space on the upper surface can be maintained at a high concentration and stable purge gas atmosphere, the inspection surface of the semiconductor wafer S can be reliably prevented from being oxidized or dewed.

As a result, the accuracy of the circuit characteristic test in the prober 1 is stabilized, and the reliability of the prober 1 is improved.

Since an air bearing is provided on the XYθZ stage 23 and a purge gas is used as a gas supplied to the air bearing, the use of the air bearing allows the purge gas to be stored in the shield case 5 without using a purge gas supply device. Will be able to supply.

Since the purge box 2 is provided with a shield case 5 for accommodating the prober 1 to form a steady state and a pass box 6 for taking the semiconductor wafer S in and out of the shield case 5, the shield case 5 The semiconductor wafer S can be taken in and out while maintaining the inside in a steady state.

Since the internal pressure of the shield case 5 of the purge box 2 is higher than the internal pressure of the pass box 6,
The gas in the shield case 5 only slightly flows to the pass box 6 side, and the gas in the shield case 5
The purge gas does not flow to the side, and the purge gas atmosphere in the shield case 5 is not agitated when the semiconductor wafer S is taken in and out, so that the surface of the sample can be maintained in a high-concentration purge gas atmosphere.

[Modifications] (1) In the above embodiment, the entire prober 1 is covered by the purge box 2, but it may be covered only around the purge space. If at least the periphery of the purge space is covered, the same operation and effect as those of the above embodiment can be obtained.

(2) Although the manual type is used as the prober 1 in the above embodiment, the present invention is not limited to this, and another type of prober may be used. In this case, the same operation and effect as those of the above embodiment can be obtained.

[0044]

As described in detail above, according to the present invention,
The following effects are obtained.

(1) Since a purge gas supply system for directly blowing a purge gas onto the surface of the sample and a purge box for forming a steady state around the sample are provided, the surroundings of the sample are maintained in a steady state to maintain a high concentration. A stable purge gas atmosphere can be maintained. Accordingly, it is possible to reliably prevent the inspection surface of the sample from being oxidized or dewed.

As a result, the accuracy of the characteristic test using the prober is stabilized, and the reliability of the prober is improved.

(2) Since the air bearing is provided and the purge gas is used as the gas supplied to the air bearing, the purge gas can be supplied into the purge box by using the air bearing.

(3) Since the purge box is provided with a shield case that houses the entire apparatus and forms a steady state, and a pass box through which the sample enters and leaves the shield case, the inside of the shield case is kept in a steady state. The sample can be taken in and out while maintaining the temperature.

(4) Since the internal pressure of the shield case of the purge box is set higher than the internal pressure of the pass box, the gas in the shield case flows to the pass box side, and when the sample is taken in and out, the purge gas atmosphere in the shield case changes. Without stirring, the surface of the sample can be maintained in a highly-concentrated purge gas atmosphere.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a state where a prober according to an embodiment of the present invention is housed in a purge box.

FIG. 2 is a perspective view showing a state in which the prober according to the embodiment of the present invention is housed in a purge box.

FIG. 3 is a front view showing a prober according to the embodiment of the present invention.

FIG. 4 is a plan view showing a prober according to the embodiment of the present invention.

FIG. 5 is a side view showing a prober according to the embodiment of the present invention.

[Explanation of symbols]

1: prober, 2: purge box, 5: shield case, 6: pass box, 7: window, 8: internal working glove, 9: release valve, 10: pressure gauge, 11: wafer cassette, 12: communication port , 13: internal door, 14, 15: support rail, 16: open / close door, 18: pressure gauge, 22: base, 2
3: XYθZ stage, 24: hot chuck, 25:
Purge plate, 26: base plate, 27: probe, 28:
Manipulator, 29: microscope, 30: guide rail,
31: nitrogen purge nozzle.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hikaru Narita 2-6-8 Kichijoji Honcho, Musashino City, Tokyo F-term in Japan Micronics Co., Ltd. (reference) 2G003 AA00 AD01 AD04 AG04 AH07 2G011 AA17 AB04 AB06 AC06 AC13 AC14 AC31 AC33 AD01 AE03 AE11 2G032 AF06 AK05 4M106 DD01 DD22 DD30 DG03 DJ01

Claims (4)

[Claims] 1. A prober for testing characteristics of a sample having a circuit or the like formed on a surface thereof in a purge gas atmosphere, wherein a purge gas is blown directly to a surface of the sample to make the surface of the sample a high-concentration purge gas atmosphere. And a purge box that covers at least the periphery of the sample and forms a steady state in which the entire surface of the sample is in a high-concentration purge gas atmosphere and the concentration decreases with distance from the surface of the sample. And a prober. 2. The prober according to claim 1, wherein an air bearing is provided on a mounting table on which the sample is mounted, and the mounting table is accommodated in the purge box, and the purge gas is supplied to the air bearing. And supplying a purge gas into a purge box by using the prober. 3. The prober according to claim 1, wherein the purge box is provided continuously with the shield case that accommodates the entire apparatus and forms the steady state, and is open to the outside. A prober having an opening / closing door, and a pass box for adjusting the concentration of the purge gas to the concentration in the shield case and for putting the sample into and out of the shield case. 4. The prober according to claim 3, wherein the internal pressure of the shield case of the purge box is higher than the internal pressure of the pass box.