CN2796083Y - Scanning generator - Google Patents

Abstract

The utility model discloses a scanning generator which is composed of a pair of scanning deflection plates, a scanning generator, a scanning deflection power supply, an air bearing, a linear electric motor, a uniformity controller, a driver of the linear electric motor, a movable Faraday cup, a target plate, a main controller and an accelerometer, wherein a wafer is loaded on the target plate and the uniformity controller adopts a parallel 16 bit FORTH processor with a high speed arithmetic capability. The utility model has the advantages of wide application range and strong practicability, the utility model can be used for the uniformity detection and the uniformity correction of a beam current, the beam current is uniformly injected, the uniformity of the injection sheet dosage is guaranteed and the repeatability is good.

Description

The scanning generating means

Technical field

The utility model relates to a kind of scanning generating means, relates in particular to the scanning generating means in a kind of ion implantor.

Background technology

Along with the development of semiconductor integrated circuit technology, integrated level is more and more higher, and circuit scale is increasing, and the unit component size is more and more littler in the circuit, therefore each semiconductor manufacturing equipment is had higher requirement; Ion implantor is as one of key equipment of semiconductor ion doping processing line, very high requirement has also been proposed, the requirement ion implantor has: whole aircraft reliability is good, the production efficiency height, the wide energy range of multiple charge state ion is injected, accurately the control bundle injects the energy accuracy of measurement, accurately control Shu Chundu, low grit pollutes, the complete machine Automatic Control, annotate sheet uniformity and good reproducibility, multiple function and features such as the injection of Shu Pinghang wide-angle, wherein high efficiency, accurately control Shu Chundu, annotate tablet amounts uniformity and good reproducibility, performances such as Shu Pinghang wide-angle injection depend on the scanning generation systems of ion implantor.

Add the mechanical scanning generating means for the electric scanning on the present ion implantor, electric scanner wherein can only be exported the triangular waveform of single scanning frequency, can not change scanning frequency, for the mechanical scanning generating means, only single sweeps out ion beam at both direction, the Shu Jinhang uniformity of sweeping out is not detected and homogeneity correction, make the distribution of line on wafer not really even.

Summary of the invention

In order to solve the problem of above-mentioned existence, the utility model provides a kind of scanning generating means, and the ion beam current of sweeping out is evenly distributed on the wafer, thereby obtains very high uniformity.

The utility model provides a kind of scanning generating means in order to achieve the above object, and this scanning generating means is made up of a pair of scan deflection plate, sweeping generator, scan deflection power supply, air-bearing, linear electric motors, uniformity controller, linear motor driver, mobile faraday, target disc, master controller and accelerometer; Wherein load wafer on the target disc, adopt parallel 16 FORTH processors in the uniformity controller with high-speed computation ability; Linear electric motors link to each other with air-bearing, and air-bearing connects target disc.

Master controller sends sweep waveform to sweeping generator, uniformity controller sends slope triggering signal driver sweep generator and produces triangular waveform, send to the scan deflection power supply, amplification by the scan deflection power supply, produce above the scan deflection plate that satisfactory scanning voltage is loaded into the flare shape, the beam level direction is swept out, parallel lens makes parallel being injected on the wafer on the target disc of the line swept out, uniformity controller produces the sine wave signal and the acceleration signal of control linear electric motors, give linear motor driver and drive the linear electric motors motion, and drive air-bearing and target disc and the wafer that is adsorbed on the target disc is made vertical scan motion; Mobile faraday receives the signal of master controller, moves the uniformity that detects line on the wafer, and gives master controller with the message transport that is obtained.

Description of drawings

Fig. 1 is a scanning generating means structure chart of the present invention;

Fig. 2 is the flow chart of bundle scan calibration;

The beam pattern of Fig. 3 for recording with mobile faraday in the whole algorithm process;

Fig. 4 is the schematic diagram of the horizontal beam homogeneity sampling of mobile faraday;

Fig. 5 is the schematic diagram of mobile faraday in the static sampling of vertical scanning period.

Embodiment

Below in conjunction with the drawings and specific embodiments the utility model is described in further detail, as shown in Figure 1, a kind of scanning generating means by sweeping generator 1, scan deflection power supply 2, a pair of scan deflection plate 3, master controller 4, uniformity controller 5,, linear motor driver 6, parallel beam lens current supply 7, parallel lens 8, mobile faraday 9, target disc 11, air-bearing 12, linear electric motors 13 and accelerometer 14 form; Wherein load wafer on the target disc 11, adopt parallel 16 FORTH processors in the uniformity controller 5 with high-speed computation ability.

Described sweeping generator 1 produces certain deflecting voltage and is based upon the electric scanning waveform of the horizontal direction on this deflecting voltage basis;

Described scan deflection power supply 2 amplifies deflecting voltage and the sweep waveform that sweeping generator 1 produces, it is added on the scan deflection plate 3, thus the deflection that Shu Jinhang is certain or sweep out in the horizontal direction;

The target disc 11 of described air-bearing 12, linear electric motors 13 and loading wafer is formed the mechanical scanning system of vertical direction, makes wafer carry out scanning motion in vertical direction;

Described mobile faraday 9 carries out the uniformity detection by moving horizontally;

The uniformity of carrying out described uniformity controller 5 detects and proofreaies and correct and produce control signal and controls the target disc 11 that linear electric motors 13 drive air-bearings 12 and load wafer by linear motor driver 6 and move up and down;

The scanning motion of described master controller 4 major controls and the whole scanning system of coordination.

Scanning generating means operation principle: as shown in Figure 1, master controller 4 sends the slope of composition sweep waveform (every section piecewise linear curve with slope and final position definition) and the RAM that position data arrives 1 li of sweeping generator, send the slope triggering signal by uniformity controller 5 then, driver sweep generator 1 produces triangular waveform and sends to scan deflection power supply 2, amplification by scan deflection power supply 2, the meet the requirements scanning voltage of (under certain deflecting voltage) of generation is loaded into above a pair of scan deflection plate 3 that is half horn shape, line is swept out in the horizontal direction, and the effect by parallel lens 8 makes parallel being injected on the wafer on the target disc 11 of the line swept out.Uniformity controller 5 produces the sine wave signal and the acceleration signal of control linear electric motors 13, give linear motor driver 6 and drive linear electric motors 13 actions, linear electric motors 13 drive air-bearing 12 and the target platform 11 that is attached thereto and the wafer that is adsorbed on the target disc 11 and do vertical scan motion under the position feedback effect of accelerometer 14, so just finished the two-dimensional scan campaign.

Will carry out the sweep waveform calibration before wafer doping is injected, idiographic flow loads certain deflecting voltage V earlier as shown in Figure 2 _cMake mobile faraday 9 receive maximum line value, mobile then faraday 9 measures line, draw out bundle section curve (being U in the flow chart (X)) and with bundle section algorithm: promptly select mobile faraday's 9 reception lines, master controller 4 says the word and drives mobile faraday's 9 horizontal movements, begin to read line to first appointed positions, read the line of hundreds of points continuously, horizontal direction is position coordinates (dividing 49 vertical lattice), vertical direction is line size (dividing 20 HORIZONTAL PLAIDs), and the corresponding lattice topmost of the maximum in the line value of hundreds of points that obtained are drawn the beam profile figure.

Calculating is marked in by the figure from the line integrated value that the beam profile figure is obtained.

I _Long-pending=∫ I _sDs/w (I _sBe each point line value, it is wide that W is that mobile faraday stitches) calculate the target current integrated value.

Get 3 points in the deflecting voltage scope, the deflecting voltage of supposing first point is V ₁, the position that records its bundle spot center is X ₁The deflecting voltage of second point is V ₂, the position that records its bundle spot center is X ₂The deflecting voltage of the 3rd point is V ₃, recording its bundle spot center is X ₃, obtain three point (X ₁, V ₁), (X ₂, V ₂), (X ₃, V ₃), utilize least square fitting to go out to represent the position

With the straight line of voltage relationship, its computational methods are as follows:

Suppose that result of calculation is v=ax+b, then

$a=$ $\frac{\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{V}_n{X}_n-\frac{1}{3}\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{V}_n\right)\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{X}_n\right)}{\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{X}_n^2-\frac{1}{3}{\left(\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{X}_n\right)}^2},$ $b=\frac{\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{V}_n-a\underset{n=1}{\overset{3}{\mathrm{\Σ}}}{X}_n}{3}$

With a, the result of calculation substitution v=ax+b of b, the scanning voltage of the deflecting voltage value that calculates the inswept entire wafer correspondence of bunch during as linear scan (can be obtained W among Fig. 3 ₀(X)).Carry out linear scan, mobile Faraday cup 9 is measured line value everywhere, with restrainting the uniformity algorithm: after Shu Shuiping sweeps out, select mobile Faraday cup 9 to receive line, master controller 4 says the word and drives mobile faraday 9 and begin to read line as Fig. 4 horizontal movement to first appointed positions, reads hundreds of individual line values of putting continuously.The standard deviation of line value is so ${\mathrm{\σ}}_{\mathrm{\λ}}=\frac{\sqrt{\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{[i_j\left(n\right)-\stackrel{\‾}{I_1}]}^2}}{\sqrt{N-1}},$ And relative standard deviation $\frac{{\mathrm{\σ}}_X}{\stackrel{\‾}{I_1}}\×100\%$ Be uniformity in the row, wherein $\stackrel{\‾}{I_1}=\frac{\underset{n=1}{\overset{N}{\mathrm{\Σ}}}i\left(n\right)}{N},$ The each point line value that i (n) measures for mobile Faraday cup 9.Draw out line value curve (as the S among Fig. 3 ₀And calculate its standard deviation and peak-to-peak value (X)).

The line uneven distribution that occurs at linear scan reads up-to-date correction waveform data, and it is written into sweeping generator 1, carries out correct scan.Whether relative standard deviation and the peak-to-peak value index drawing out line value curve (as the Sc among Fig. 3 (X)) once more and calculate line have reached the setting requirement, if reach, then begin to annotate the sheet process, otherwise proceed to proofread and correct.

If do not reach the setting requirement with the uniformity and the line peak-to-peak value that measure after the scanning of correct scan waveform, then need to adopt bundle sweep waveform calibration algorithm: the scanning voltage the during linear scan that will at first obtain is divided into the hundreds of section from the minimum to the maximum, carry out the line calibration at each section, the line that draws uniformity distributes, sweep waveform is revised once more, and its calibration algorithm is as follows: $s_1\left(n\right)=s_0\left(n\right)\×\frac{i_1\left(n\right)}{I_0},$ I wherein ₁The line value of each point that measures when (n) calibrating for last time, I ₀Line mean value during for calibration scan, s ₀(n) be the slope value array that last time, calibration was used, s ₁(n) be new slope value array (as the Wc among Fig. 3 (X)).

Scanning voltage waveform after utilize upgrading carries out correct scan, reaches the setting requirement until the uniformity and the line peak-to-peak value of line, just can annotate sheet.

The utility model is not limited to the foregoing description, and for the professional in present technique field, any improvement that the utility model embodiment is made or change can not exceed the protection range of spirit of the present utility model and claims.

Claims (1)

1, a kind of scanning generating means is characterized in that this scanning generating means is made up of a pair of scan deflection plate, sweeping generator, scan deflection power supply, air-bearing, linear electric motors, uniformity controller, linear motor driver, mobile Faraday cup, target disc, master controller and accelerometer; Wherein load wafer on the target disc, adopt parallel 16 FORTH processors in the uniformity controller with high-speed computation ability;

Master controller sends sweep waveform to sweeping generator, uniformity controller sends slope triggering signal driver sweep generator and produces triangular waveform, send to the scan deflection power supply, amplification by the scan deflection power supply, producing satisfactory scanning voltage is loaded into above the scan deflection plate, the beam level direction is swept out, parallel lens makes parallel being injected on the wafer on the target disc of the line swept out, uniformity controller produces the sine wave signal and the acceleration signal of control linear electric motors, give linear motor driver and drive the linear electric motors motion, and drive air-bearing and target disc and the wafer that is adsorbed on the target disc is made vertical scan motion; Mobile faraday receives the signal of master controller, moves the uniformity that detects line on the wafer, and information is passed to sweeping generator.

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