JPS62205637A - Semiconductor wafer prober - Google Patents

Abstract

PURPOSE:To provide a defective marking immediately after measurement, by attaching a marker, which gives a mark on the surface of a semiconductor wafer that is sucked to a transfer arm, to an X/Y stage mechanism. CONSTITUTION:A marker (inker) INK is attached to an XY stage X-Y, which is arranged in the horizontal direction. After measurement, the position information of each chip in a semiconductor wafer to be measured, which is conveyed on a transfer arm TRAM, can be readily computed based on the relative position information of a wafer chuck CT and the transfer arm TRAM. The position of the XY stages S-Y is controlled based on the position information of the defective chip obtained from the result of the measurement. The marker is moved in correspondence with the defective result of the measurement can be performed immediately after the measurement.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a semiconductor wafer blower.
For example, it relates to a technique that is effective when used to simultaneously measure a plurality of semiconductor chips.

[Conventional technology]

When the wafer prober is completed, the semiconductor integrated circuits are placed on the semiconductor wafer in the shape of a substrate. The semiconductor integrated circuits thus completed on the semiconductor wafer are tested to see if they satisfy desired circuit functions, characteristics, etc. before being individually divided and packaged. A semiconductor wafer blower is used in this blowing step. A semiconductor wafer prober applies a probe to a bonding pad of a semiconductor integrated circuit completed on the semiconductor wafer, supplies an input signal from a tester, and transmits an output signal from the semiconductor integrated circuit to the tester. Regarding the semi-solid two-wheeled blower, see, for example, the magazine "Electronic Materials" published in November 1978, pages 139 to 143.

In order to improve the efficiency of probing semiconductor wafers, simultaneous measurements are performed by bringing probe needles into contact with multiple chips at the same time. In particular, in a semiconductor memory device such as a dynamic RAM (random access memory), bonding pads (measuring electrodes) are arranged only on two opposing sides, as shown in FIG. Thereby, a fixed probe board having fixed probes aligned with a plurality of semiconductor chips, for example 4 to 8, can be easily formed. By bringing the probe needle into contact with a plurality of chips simultaneously in this manner, it is possible to measure a plurality of semiconductor chips simultaneously, and the measurement time can be significantly shortened.

[Problem that the invention seeks to solve]

However, when using a fixed probe board that makes contact with multiple chips at the same time, a large number of probe needles are provided at a high density, so the mounting space for multiple markers is required to mark defective chips. It's gone. Therefore, on the semiconductor wafer for which the above-mentioned measurement has been completed, only marking is performed separately from the measurement using a semiconductor wafer blobber provided with only markers. For this reason, an expensive semi-solid wafer prober is used only for marking, which reduces the operating rate of the semiconductor wafer prober. management becomes troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semi-phosphorescent wafer blobber that enables simultaneous measurement of multiple chips and a marking function according to the measurement results.

The above and other objects and novel features of this invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the semiconductor wafer to be measured is placed between the measurement stage, which is provided with a suction part whose part is pushed up against the reference surface for the transfer of the semiconductor wafer, and the semiconductor wafer transport means. Using a transfer arm that picks up and transfers the wafer by a suction part provided in a part other than the part corresponding to the suction part, a marker for marking is placed on the surface of the semiconductor wafer that is suctioned to the transfer arm. The X/Y stage mechanism is designed to allow one inch to be used for marking defective chips.

[For production]

According to the above-mentioned means, it becomes possible to mark defects immediately after measurement using the X/Y stirge for the marker.

〔Example〕

FIG. 1 shows a schematic front view of a stage mechanism in a semiconductor wafer prober according to the present invention.

In this embodiment, although not particularly limited, the X/Y stage is arranged vertically. In other words, the X stage is
The beam moves laterally along a vertical plane. For this reason, the X stage is not particularly limited in order to support relatively heavy devices such as the Y stage mechanism and the X stage, which will be described later, in a highly stable manner. A rail RL is provided. X base
The BS is moved in the horizontal direction by a screw pair with a screw shaft (lead screw) XS, which is rotated by an X-drive pulse motor XDM on the rail RL as a guide. A bearing SB for maintaining the screw shaft XS in a constant direction is provided on the other end side of the screw shaft XS. Thereby, highly accurate positional movement control of the X base XBS is performed in accordance with the rotation angle of the pulse motor XDM and the screw pitch of the screw shaft XS. Note that the X-base XBS may use a linear slide mechanism using bearings.

Y base YBS, pulse motor Y for Y drive similar to the above
It is moved in the vertical direction by a screw pair with a screw shaft (lead screw) YS whose rotation is controlled by DM. In order to maintain the surface of the Y base YBS constant, a pair of rails are provided that are connected to both sides of the Y base YBS with a sliding pair using a bellows or the like. Also,
Although not particularly limited, in order to maintain the Y-axis constant in the vertical direction, the other end of the twisted shirt YS and the pair of rails has a sliding pair with a guide rail XGR running parallel to the rail RL in the direction of movement. is defined as the X guide x
It is coupled to G. In addition, the other end of the screw shaft YS is
The guide xG is used as a bearing.

As a result, the Y base Y mounted on the X base XBS
The position of the BS is controlled with high precision in the X and Y directions along the vertical plane.

A Z stage that moves up and down in a direction perpendicular to the surface (vertical surface) of the Y base YBS is provided. In other words, the Z stage is moved in a constant horizontal direction. This Z stage is hyperactively controlled by a Z drive pulse motor indicated by a dotted line in the same figure. Also, the wafer chuck CT mounted on the Z stage has a similar ζ by pulse motor
A rotation control mechanism in the θ direction with respect to the Z axis is provided.

Although the wafer chuck CT is not limited to the above, a plurality of concentric grooves and a plurality of vacuum suction holes provided on the bottom of the grooves are provided on the surface of the wafer chuck CT, so that a half-door wafer mounted on the surface of the wafer chuck CT is provided. vacuum suction (hereinafter simply referred to as suction) on the back side of the As such a Z stage and wafer chuck, those similar to those of a known semiconductor wafer prober can be used.

The above-mentioned wafer chuck CT is used for loading and unloading the semi-solid wafer to be measured, although it is not particularly limited.
T' is selectively pushed upward relative to its reference plane. When loading and unloading the semiconductor wafer to be measured, the central portion CT' is lifted and the semiconductor wafer to be measured is attracted only at the central portion.

FIG. 5 shows a schematic sectional view showing one embodiment of the wafer chuck. The structure of the wafer chuck will now be described with reference to the same figure.

The wafer chuck CT has a cavity 1 connected by a plurality of suction holes 2 on its surface. Among the plurality of suction holes 2, those arranged at the same position from the center point are connected to each other by concentric circular grooves. The cavity 1 is a cylindrical cavity, and is commonly connected to the plurality of suction holes 2. The central portion CT° of the wafer chuck CT has a plurality of suction holes 2′ and a cavity 1′ similar to the above. This central CT' is not particularly limited, but
By the rotational drive of the pulse motor PM, the suction surface of the wafer chuck CT is lifted to a position shown by the dotted line in the figure with respect to the reference surface of the wafer chuck CT. As a result, the semiconductor wafer 5 to be measured, as shown by the dotted line in the figure, is suctioned and fixed only at its center, and is carried in/out. Since the central portion CT' moves up and down with respect to the reference plane of the wafer chuck CT, the cavity 1 of the central portion CT'
゜ is guided through the suction path 3' to the tube 4, which is longer than the vertical stroke. This chive 4 is
It is coupled to a vacuum valve BB2 through a suction path provided at the base of the wafer chuck.

The cavity 1 of the wafer chuck C'r is connected to a vacuum valve BBI via a suction ii4 passing through the wafer chuck.
is combined with The base of the above wafer chuck CT is Z
The stage is driven in the Z direction by a pulse motor ZDM.

On the other hand, as shown in a plan view in FIG. 2, the transfer arm TRAM has a suction section (this embodiment This is a U-shaped arm.
has a stage mechanism that moves the surface of the suction section along the y' horizontal plane, and a rotation mechanism that rotates it approximately 90 degrees to make the surface of the suction section vertical. The stage m structure that moves the transfer arm TRAM in the horizontal direction is driven by a wire W.

That is, a wire W is connected to a driving pulley Pl connected to a driving pulse motor TDM provided at one end of a horizontally arranged fixed shaft and a free pulley P2 provided at the other end of the fixed shaft. A base (
fulcrum). A transfer arm TRAM is provided on this base. Such a wire drive method is used, for example, in a known XY plotter. As a result, the fulcrum of the transfer arm TRAM can be provided with a rotation mechanism that rotates it by 90'' with a simple configuration.

The four wafers to be measured are stored in a wafer cassette 1- (indicated by dotted lines in FIG. 1 and solid lines in FIG. 2) mounted on an elevator mechanism. This wafer cassette is
As is well known, a plurality of slits are provided on both inner side surfaces, and both ends of a plurality of wafers are inserted into each of these slits in a horizontal direction. Although not particularly limited, a plurality of wafer cassettes as described above are vertically stacked and mounted on the elevator mechanism.

The above elevator mechanism is a transformer arm 'I'
The semiconductor wafer is moved so that the position of the semiconductor wafer at which measurement is to be started coincides with the horizontal position of the RAM. The transfer arm TRAM is moved to the right end in the figure, and takes out the semiconductor wafer on which measurement is to be started by sucking and fixing the semiconductor wafer from its lower surface using the suction section.

Although the transfer arm TRAM is not particularly limited,
After the semiconductor wafer (indicated by a dotted line in the figure) is moved to a predetermined position on the left in the figure, it is vertically erected to correspond to the reference plane of the wafer chuck CT. In this state, the wafer chuck CT side is moved to a position corresponding to the transfer arm TRAM under the control of its stage mechanism, and its central portion CT' is pushed up to contact the back surface of the semiconductor wafer to be measured. Thereafter, the vacuum valve BB2 shown in FIG. 5 is opened to start vacuum suction, and at the same time, the vacuum suction on the transfer 1 arm TRAM side is stopped. As a result, transfer arm T I2
A semiconductor wafer to be measured is transferred between AM and wafer chuck CT.

This 2f, (, by relatively moving the transfer arm TRAM and wafer chuck CT,
By lowering the central portion CT' of the T to the reference plane and opening the vacuum pulp BBI, the semiconductor wafer to be measured is vacuum suctioned on the entire surface of the wafer chuck CT.

The semiconductor wafer to be measured, which is attracted to the wafer chuck CT, is aligned with a fixed probe using the stage mechanism, which includes alignment similar to that of a known semiconductor wafer prober. The unloading of the semiconductor wafer to be measured after the measurement is performed in the reverse order of the loading operation described above.

In this embodiment, the position of the semiconductor chip formed on the semiconductor wafer can be accurately defined by the needle alignment, and the wafer chuck CT and transfer arm TR
The following marking mechanism is provided by taking advantage of the fact that when transferring a semiconductor wafer to be measured to and from an AM, positional deviation does not occur as in the case of using a conventional Bernoulli chuck.

That is, as shown in FIG. 2, a marker (inker) INK is attached to an XY stage X-Y arranged in the horizontal direction. Since the diameter of the semiconductor wafer to be measured is relatively small (several inches), this XY stage for markers uses a stage mechanism with a relatively small length (small amount of movement) that allows the marker to be moved to any point over the entire surface of the wafer. Realized. As a result, the positional information of each chip on the half-door wafer to be measured that has been carried out to the transfer arm TRAM after the measurement is completed can be easily obtained from the relative positional information between the wafer chuck CT and the transfer arm TRAM. It is calculated. Therefore, marking is performed by moving the marker corresponding to the defective chip by controlling the position of the XY stage X-Y based on the position information of the defective chip based on the measurement results. After this marking is completed, the ink adhered to the semiconductor wafer to be measured is dried using a heater including, but not limited to, an infrared lamp, and returned to the original Univaccent (storage container) CAA mounted on the elevator mechanism. It will be brought in.

As a result, even when a fixed probe board that enables simultaneous measurement of a plurality of semiconductor chips is used, defective marking can be performed immediately after the measurement is completed according to the measurement results. This eliminates the need to use the prober only for marking semiconductor wafers, thereby improving the operating rate of the semiconductor wafer prober. In addition, there is no need to assign a model part number to the semiconductor wafer by one minute and make a one-to-one correspondence with the measurement data, which simplifies the management of the semiconductor wafer and measurement data in the blobbing process. .

FIG. 3 shows a schematic external view of a semiconductor wafer prober and a high frequency test head according to the present invention.

In the semiconductor wafer prober of this embodiment, as shown in FIG. 1, the stage mechanism is arranged vertically, so that the stage mechanism (X-Y> On the other hand, the control unit i-CO
The r-4Ts are combined in a vertical stacking manner. Further, the wafer cassettes are also stacked vertically on the elevator. Therefore, when each unit is stacked in a stacked manner as in this embodiment, since the stroke in the Z direction is only 1 u or less, the width can be narrowed when it is vertically mounted, and the stage mechanism can be made larger. As the functionality expands, the floor space can be significantly reduced by increasing the vertical dimension.

If the floor space can be reduced in this way, a large number of semiconductor wafer probers can be installed on a small floor, and the distance to an IC tester (computer) that performs parallel tests using a large number of semicircular wafer probers can be shortened. As a result, the length of the signal transmission cable can be shortened, facilitating high-speed testing. In addition, in the same figure, the CRT is
There is a monitor television used for needle alignment, etc.
The PNL is a number in which each MifM switch is assigned.

In the vertical type wafer prober as described above, the surface of the semiconductor wafer to be measured is the side surface of the semiconductor wafer prober (
vertical plane). Correspondingly, the fixed probe board is likewise loaded parallel to the vertical plane. For this reason, although there are no particular limitations, a probe in which a fixed blower board is loaded into the opening provided on the side surface
\Sodo mechanism will be established. In addition, when performing one high-frequency test, a high-frequency probe with a spring property is held from the opening, and a large weight is attached to the stationary probe board loaded in the semiconductor wafer prober. The high frequency test head T11 can be coupled by moving in the horizontal direction. In order to facilitate alignment of such a high frequency test head, an alignment guide GD is provided in the opening of the semiconductor wafer blower. On the other hand, the high-frequency test head TI is allowed to move freely on the floor by means of wheels (trucks).

In such a configuration, even if f(ffl) of the high-frequency test head TH is large, it can be moved with a relatively small force, and it can be coupled to the semiconductor wafer prober using the above-mentioned gas, C, and GD. In addition, the above-mentioned high-frequency test head must be attached and detached by running it on a rail that is connected with the semiconductor unihub l cover with high precision. , it can be S.

The fixed probe board also supports high frequency test head T.
As a device to be installed on the H side, the fixing block 1:2
- The probe of the board may be connected to the half-quad wafer. This provides advantages such as shortening the transmission path between the fixed probe board and the cable.

The effects obtained from the above examples are as follows.

(11) The conductor wafer to be measured is placed between the measurement mounting table and the semiconductor wafer forwarding means (a part of which is equipped with a suction part that is pushed up against the reference surface for the transfer of the semiconductor wafer). A transfer arm is used which transfers the semiconductor wafer by suction by a suction part provided corresponding to the suction part on the back side, and the semiconductor wafer is suctioned to the transfer arm. By attaching markers for marking the surface to the X/Y stage mechanism and marking each defective chip, it is possible to measure multiple semiconductor chips simultaneously, even when using a fixed probe board. Immediately after completion of the measurement, defect marking can be performed according to the measurement results. As a result, it is not necessary to use the half-folding wafer prober only for marking, so it is possible to improve the operating rate of the semiconductor device.

(2) Due to (1) above, in the simultaneous measurement of multiple chips, there is no need to add a product number to the semiconductor wafer and make a one-to-one correspondence with the measurement data. This has the effect of simplifying the management of measurement data. (3) Since the X/Y stage on which the wafer chuck is installed is a vertical type that moves along the vertical plane, the stroke in the Z direction in the stage mechanism is only 111i or less. Since the width can be reduced and the cassette unit, control unit, roll unit, etc. can be stacked vertically, the floor space occupied by one semiconductor wafer can be reduced.

(4) Due to (3) above, a large number of semiconductor wafer probers can be installed on a dust-free floor, making efficient use of the dust-free floor, and shortening the distance to the tester so that short cables can be used. This has the effect of enabling high-speed testing.

(By making the Full It is possible to prevent the ink from adhering to the wafer surface and causing damage.Furthermore, since marking is performed with the semiconductor wafer held horizontally after the measurement is completed, the surface tension of the marking ink increases. It is possible to prevent contact failure due to contamination of the contact end of the probe.Thereby, an effect can be obtained in that the original measurement of hyperconversion can be performed.

Although the invention made by the present inventor has been specifically explained based on Examples above, this invention ζ is not limited to the above Examples, and can be modified in various ways without departing from the gist thereof. Needless to say. For example, in FIGS. 1 and 2, a pre-alignment stage may be provided to center the semiconductor wafer taken out from the wafer cassette and to detect its orientation flat. . By providing such a pre-alignment stage, it is possible to efficiently align the semiconductor wafer on the wafer chuck top. Also, the transfer arm consists of a pair for loading and unloading the semiconductor wafer. Good too.

When a pair of transfer arms is provided in this way, the unloading transfer arm is used to perform the above marking, while the unloading transfer arm is used to take out the semiconductor wafer to be measured next and perform the above marking. Pre-alignment etc. can be performed in parallel.

Further, on the condition that the semiconductor wafer to be measured is transferred to and from the transfer arm as described above, the stage mechanism provided with the wafer chuck may be a horizontal type like that of a known semiconductor wafer prober.

Further, it may be provided with a scanning device that performs pattern recognition for automatic needle alignment with the semiconductor wafer, a sensor that measures variations in the thickness of the semiconductor wafer, and sets the needle pressure optimally, or the like. In addition, when the needle alignment is performed visually such as with a semi-automatic semiconductor wafer probe, a microscope or imaging device is installed in the opening shown in FIG. 2 above.

This invention can be widely used as a semiconductor wafer prober.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this section is as follows. That is, the - part is used for transferring the semiconductor wafer, and the semiconductor wafer to be measured is placed on the back side between the measurement stage equipped with a suction part that is pushed up against the table surface and the semiconductor wafer transport means. Using a transfer arm that transfers the semiconductor wafer by suction using a suction part provided on the side corresponding to the part other than the part corresponding to the suction part, 0 and marking are performed on the surface of the semiconductor wafer that is suctioned by this transfer arm. By attaching a marker to the X/Y stage mechanism and marking defective chips, even when using a fixed probe board that enables simultaneous measurement of multiple semiconductor chips, the measurement results are immediately available after the measurement is completed. The effect is that defect marking can be performed according to the following.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a stage mechanism in a semiconductor wafer prober according to the present invention, FIG. 2 is a schematic plan view of its transfer arm and an XY stage for marking, and FIG. FIG. 4 is a schematic external view of a high-frequency test head, FIG. 4 is a layout diagram of semiconductor chips, and FIG. 5 is a schematic cross-sectional view showing an embodiment of a wafer chuck. XDM, YDM, ZDM, TDM...Pulse motor, R
L...Rail, SB...Bearing, XBS...X base, Y
BS...Y base, CT...wafer chuck, CT'
・・Central part, XGR・・X guide rail, XS・・X
Shaft (lead screw), YS...Y shaft (
lead screw), XC・・X guide, X-YTB・
・Stage mechanism, TRAM...Transfer arm, I
NK...marker, X-Y...xy stage, Pi.

Claims (1)

[Claims] 1. A measurement mounting table, a part of which is provided with a suction part that is lifted with respect to a reference surface when a semiconductor wafer to be measured is transferred, and the semiconductor wafer corresponds to the suction part on the back side thereof. a transfer arm that has a suction part provided corresponding to a part other than the part to which the part is attached, and which transfers the part;
A semiconductor wafer prober comprising: an X/Y stage mechanism provided with a marker for marking a surface of the semiconductor wafer while it is attracted to the transfer arm. 2. The above measurement mounting table moves along the vertical plane in X/Y
The transfer arm is provided in the stage mechanism and attracts the surface of the semiconductor wafer to be measured in a substantially vertical state.The transfer arm has the function of horizontally/vertically moving the semiconductor wafer to be measured, and the The semiconductor according to claim 1, wherein the Y stage moves the marker along the surface of the semiconductor wafer held by the transfer arm in a substantially horizontal state. wafer prober.