CN201858959U

CN201858959U - Non-contact thickness automatic measuring system for semiconductor wafers

Info

Publication number: CN201858959U
Application number: CN2010205469713U
Authority: CN
Inventors: 李福荣; 陈罡; 朱洪伟
Original assignee: SYNWORLD INSTRUMENTS (SHANGHAI) CO Ltd
Current assignee: SYNWORLD INSTRUMENTS (SHANGHAI) CO Ltd
Priority date: 2010-09-29
Filing date: 2010-09-29
Publication date: 2011-06-08
Anticipated expiration: 2020-09-29

Abstract

The utility model provides a non-contact thickness automatic measuring system for semiconductor wafers. The non-contact thickness automatic measuring system comprises a signal sensing module, a signal processing and calculating module and a drive module; the single sensing module comprises a testing platform, two sensors arranged respectively on the upper side and the lower side of the testing platform and a photoelectric sensor arranged under the testing platform; the single processing and calculating module used for processing singles sent by the signal sensing module comprises a single processing module, an analog-digital conversion module, a microprocessor, a step motor driver, an electromagnetic valve driver, an Ethernet network interface and a sensor interface; and the drive module comprises a sucking disc, an X-direction limiting sensor, a Z-direction limiting sensor, a return sensor, a vacuum electromagnetic valve and three step motors controlling the X-direction motion, the Z direction motion and the rotating motion of the sucking disc respectively. The non-contact thickness automatic measuring system for the semiconductor wafers can effectively, quickly, accurately and flexibly realize the thickness measurement under various modes, and greatly reduces the damages on the wafers by adopting the non-contact working mode.

Description

Semiconductor wafer non-contact type thickness automatic measurement system

Technical field

The utility model relates to a kind of measuring system of semiconductor wafer thickness, especially, relates to a kind of semiconductor wafer non-contact type thickness automatic measurement system.

Background technology

Need in the semiconductor wafer manufacturing process its thickness and thickness deviation are measured.Usually, semiconductor wafer manufacturing enterprise need the different links in whole process flow in especially to the thickness of wafer, parameters such as thickness deviation are measured and are monitored, in order to improving the product quality of each road technology, thus the parameter index compliant of the finished product that guarantees finally to dispatch from the factory or reach requirement of client.

The manual mode that traditional thickness measure mode is needs that the operator is manual to be placed into semiconductor wafer in the middle of two probes, measures thickness results after starting a trigger pip.This metering system efficient is low, and the mode ratio of manually placing wafer be easier to wear and tear wafer and increase fragment rate, and this manual type can only be measured single position on the wafer simultaneously.Measure a plurality of positions of wafer if desired, owing to be artificial location, site error also can be relatively big, is difficult to guarantee the accurate and effective of measurement result, thereby influenced final product quality.

Summary of the invention

Technical problem to be solved in the utility model provides the automatic test mode of a kind of contactless semiconductor wafer thickness, can realize multiple test pattern, and can reach the index of certain precision and repeatability.

The utility model is that to solve the problems of the technologies described above the technical scheme that adopts be a kind of semiconductor wafer non-contact type thickness Auto-Test System, wherein, comprising:

The sensing module, it comprises: test platform, place test platform two sensors of both sides up and down respectively, and the photoelectric sensor that places the test platform below;

The signal Processing computing module, it links to each other with the sensing module, comprising: signal processing module, analog-to-digital conversion module, microprocessor, step motor drive, solenoid-driven, Ethernet interface and sensor interface are used for the signal that the sensing module transmits is handled;

Driver module, it comprises sucker, X is to limit sensors, Z is to limit sensors, reseting sensor, vacuum solenoid and control respectively sucker X to, Z to three stepper motors that rotatablely move.

As above-mentioned semiconductor wafer non-contact type thickness Auto-Test System, wherein, two sensors in the sensing module are capacitance type sensor.

As above-mentioned semiconductor wafer non-contact type thickness Auto-Test System, wherein, the photoelectric sensor in the sensing module is a reflective photoelectric sensor.

The utility model can be more effective quick owing to having adopted above-mentioned technical scheme, accurately, and the thickness measure purpose under the realization various modes of dirigibility.The utility model is contactless working method, will reduce greatly the damage of wafer.

Description of drawings

Fig. 1 is a semiconductor wafer non-contact type thickness Auto-Test System structural representation of the present utility model;

Fig. 2 (a) is the scanning area synoptic diagram of the utility model under the measurement pattern of center;

Fig. 2 (b) is the scanning area synoptic diagram of the utility model under five point measurement patterns;

Fig. 2 (c) is the scanning area synoptic diagram of all the other rings of the utility model under the scanning survey pattern;

Fig. 2 (d) is the scanning area synoptic diagram of the center ring of the utility model under the measurement pattern of center;

Fig. 3 is the workflow diagram of semiconductor wafer non-contact type thickness Auto-Test System of the present utility model.

Embodiment

Below in conjunction with the drawings and specific embodiments the utility model is described further.

Fig. 1 is a semiconductor wafer non-contact type thickness Auto-Test System structural representation of the present utility model.Native system is applicable to multiple thickness, and the thickness measure of the semiconductor wafer of size is used.Below in conjunction with accompanying drawing, carry out a series of detailed descriptions, illustrate the course of work of native system.

Native system is made up of 3 sub-function module: sensing module, signal Processing computing module, driver module.

The sensing module places the capacitance type sensor 1 and the capacitance type sensor 5 of test platform both sides about in the of 11 respectively by the test platform among Fig. 1 11, places the reflective photoelectric sensor 7 of test platform 11 belows to form.Test platform 11 is used to place semiconductor wafer 12 to be measured.Capacitance type sensor 1 is used for sense capacitance formula sensor 1 and leaves the distance D 1 of semiconductor wafer 12 upper surfaces, and capacitance type sensor 5 is used for sense capacitance formula sensor 5 and leaves the distance D 2 of semiconductor wafer 12 lower surfaces.All fix owing to measure

front sensor

1,5, between distance be D, so the thickness d=D-(D1+D2) of the semiconductor wafer of measuring 12.

The signal Processing computing module is by the signal processing module among Fig. 1 26, analog-to-digital conversion module 25, and microprocessor 20, step motor drive 21, solenoid-driven 22, Ethernet interface 23 is formed.Signal processing module 26 will carry out the passage gating from the simulating signal that the input of sensing module comes, processing such as signal filtering, deliver to analog-to-digital conversion module 25 then, analog-to-digital conversion module 25 is delivered to microprocessor 20 with the signal digital amount that generates, after passing through a series of computings then, obtained and the thickness corresponding voltage value.By Ethernet interface 23 the thickness voltage data is sent to the master control computer at last.

Driver module is by the stepper motor among Fig. 12, stepper motor 3, and stepper motor 4, sucker 6, limit sensors 8, limit sensors 9, reseting sensor 13, vacuum solenoid 10 is formed.The motion of stepper motor 2 control sucker 6Z axle (up and down) directions.Stepper motor 3 control sucker 6X axles (about) motion of direction.The motion of stepper motor 4 control suckers 6 sense of rotation.Limit sensors 8 is used for limiting the scope of stepper motor 3 move left and right, plays a protective role.Limit sensors 9 is used for limiting the scope that stepper motor 2 moves up and down, and plays a protective role.Reseting sensor 13 is used for the direction of positioning sucker disk 6 rotation.The opening and closing of vacuum solenoid 10 control vacuum.

Introduced the composition and the function of each module above, each module often all is to intert to come work mutually in practical work process, introduces down the workflow of whole thickness measuring system below, and process flow diagram is seen Fig. 3.

Step 80, semiconductor wafer 12 arrives test platform 11, and reflective photoelectric sensor 7 has sensed semiconductor wafer 12, and is sent to system by sensor interface 24, and whole thickness measuring module is started working;

Step 81, under the control of stepper motor 2, sucker 6 rises earlier, opens solenoid valve 10, holds semiconductor wafer 12, continues to rise to the test desired height;

Step 82 is judged the work at present pattern, if center test pattern execution in step 83 then.

Step 84, if not the center test pattern, but 5 test patterns execution in

step

85,86,87 then;

Step 88, if not 5 test patterns, but scan pattern execution in

step

89,90,91,92 then;

Step 83, the voltage (voltage is corresponding with respect to the distance of semiconductor wafer with the two) of capacitance type sensor 1 and capacitance type sensor 5 difference sensing semiconductor wafer 12 upper surfaces and lower surface, the scope of measuring such as the cross part of Fig. 2 (a) lining, then measuring voltage is inputed to signal processing module 26, by the passage gating, processing such as simulating signal filtering input to analog-to-digital conversion module 25 again, are input to microprocessor 20 at last;

Step 85 is with step 83;

Step 86, microprocessor 20 give step motor drive 21 instructions, and the drive controlling stepper motor 4 then, and rotation semiconductor wafer 12 is measured thickness voltage simultaneously, and the cross part of the scope of measurement such as Fig. 2 (b) lining is with step 83;

Step 87, microprocessor 20 give step motor drive 21 instructions, and

control step motor

2,3,4 makes sucker 6 and wafer 12 get back to initial position;

Step 89 is with step 83;

Step 90, microprocessor 20 give step motor drive 21 instructions, and the drive controlling stepper motor 2,3 then, 4, rotate semiconductor wafer 12 simultaneously, mobile simultaneously up and down sucker 6, and measure thickness voltage simultaneously, the dash area of the scope of measurement such as Fig. 2 (c) lining is with step 83;

Step 91, microprocessor 20 give step motor drive 21 instructions, and the drive controlling stepper motor 2,3 then, 4, rotate semiconductor wafer 12 simultaneously, mobile simultaneously up and down sucker 6, and measure thickness voltage simultaneously, the dash area of the scope of measurement such as Fig. 2 (d) lining is with step 83;

Step 92 is with step 87;

Step 93, microprocessor 20 sends to main control module to all thickness voltage datas by Ethernet interface 23, handles for main control module;

Step 94, under the control of stepper motor 2, sucker 6 descends earlier, closes solenoid valve 10 simultaneously, discharges wafer 12, and wafer 12 is placed on test platform 11;

Step 95, stepper motor 2,4 in conjunction with limit sensors 9 and reseting sensor 13, resets, and prepares the test of next wafer.

More than specific embodiment of the utility model is described in detail, but the utility model is not restricted to specific embodiment described above, it is just as example.To those skilled in the art, any equivalent modifications that this semiconductor wafer non-contact type thickness automatic measurement system is carried out and substituting also all among category of the present utility model.Therefore, not breaking away from impartial conversion and the modification of having done under the spirit and scope of the present utility model, all should be encompassed in the scope of the present utility model.

Claims

1. a semiconductor wafer non-contact type thickness Auto-Test System is characterized in that, comprising:

2. semiconductor wafer non-contact type thickness Auto-Test System as claimed in claim 1 is characterized in that two sensors in the sensing module are capacitance type sensor.

3. semiconductor wafer non-contact type thickness Auto-Test System as claimed in claim 1 is characterized in that the photoelectric sensor in the sensing module is a reflective photoelectric sensor.