JP5424823B2 - Semiconductor manufacturing apparatus and semiconductor processing method - Google Patents

Description

  The present invention relates to a semiconductor manufacturing apparatus and a semiconductor processing method capable of detecting an end point at a low cost in process processing in which device miniaturization / thinning or wafer diameter increases.

  Etching apparatuses that process semiconductor wafers using plasma are widely used, and one of them is an ECR (electron cyclotron resonance) type etching apparatus. An example of this method is shown in FIG.

  A direct current is supplied from solenoid coil DC power supplies 4 and 5 to solenoid coils 2 and 3 arranged outside the chamber 1 to form a magnetic field in the chamber 1. Further, a high voltage is applied to the oscillator 6 from the DC power supply 7 for the oscillator to generate, for example, a microwave and introduce it into the chamber 1.

  Electron cyclotron resonance (ECR) is generated by the synergistic effect of the microwave and the magnetic field, and the process gas 15 introduced into the chamber 1 via the process gas flow rate controller 4 is converted into plasma to generate ECR plasma 16.

  A DC voltage is applied to the electrode 7 from the electrostatic adsorption power source 8 to adsorb the semiconductor wafer 10 to the electrode, and high frequency power is applied from the high frequency bias power source 9, and ions in the plasma are applied to the semiconductor wafer 10. Anisotropic etching with high processing accuracy is realized by drawing vertically and independently controlling the incident ion energy.

  Further, the signal obtained from the light emission pickup 11 that collects the plasma emission of the ECR plasma 16 is analyzed by the emission spectroscopic analyzer 12 to determine the end point of the etching, and the etching process is switched or the process is shifted to the end process.

  Usually, the etching process consists of a plurality of process steps, and for each process step, the processing time, the pressure in the vacuum vessel, the intensity of the direct current flowing through the solenoid coils 2 and 3, the intensity of the microwave power, the amount of process gas introduced, In addition to the strength of the high frequency power applied to the electrodes, a number of parameter settings are determined in advance.

  Then, when the processing step is switched during the etching, various parameter values are controlled to be the set values based on the setting of the next processing step. As described above, a series of parameter settings relating to an etching process including a single process step or a plurality of process steps is hereinafter referred to as a recipe.

  The device controller 13 sequentially sets a setting signal for each component device according to the recipe, monitors the monitor signal, and performs a predetermined abnormality process when an abnormality of any component device is detected. Although omitted, the apparatus controller 13 also performs monitor display for man-machine interface and transmission of monitoring data to the host computer on the equipment side.

  In semiconductor manufacturing, the yield is very important, and whether or not an appropriate etching end point can be determined greatly affects the yield. A typical example of etching end point determination is that the plasma emits light of a specific wavelength generated by excitation or vibration of gas molecules depending on the gas or by-product used, and at a specific wavelength as the processing layer is removed. This is a function for detecting a point at which most of the layer to be etched has been removed by utilizing the change in the emission intensity.

  While the end point of etching in high value-added wafer processing is becoming increasingly important, on the other hand, it is weak against various process conditions associated with miniaturization and thinning, in other words, various plasma intensity distributions. Technical difficulty is increasing, for example, that it is necessary to determine the end point when the light emission changes, or to determine the optimal end point for the entire large-diameter wafer.

Special Table 2007-525019

It is a problem to realize an end point determination with a weak light emission change with respect to various plasma intensity distributions and an optimum end point determination for the entire large-diameter wafer at a low cost.

The most important feature of the present invention is that it has means for changing the direction and position of picking up plasma emission for each process condition.

The semiconductor manufacturing apparatus of the present invention is a semiconductor manufacturing apparatus comprising means for performing end point detection of the processing to detect the plasma emission of plasma formed in the chamber for processing a semiconductor wafer, picked up the plasma emission It has the means to change the direction and position to do.

  The semiconductor manufacturing apparatus of the present invention is further characterized in that the variable means includes a rotation mechanism to which a light emitting pickup is fixed, and means for driving the rotation mechanism.

  In the semiconductor manufacturing apparatus of the present invention, the rotation axis of the rotation mechanism is perpendicular to the radial direction of the electrode on which the semiconductor wafer is placed, and the tip of the optical axis of the light-emitting pickup is variable from the center to the outer periphery of the electrode. It is characterized by doing.

Further, the semiconductor processing method of the present invention is a semiconductor processing method for determining the end point of the processing by forming plasma in the chamber and detecting plasma emission in order to process the semiconductor wafer disposed in the chamber. , characterized by varying the direction and position to pick up the plasma emission for each processing step.

  In the semiconductor processing method of the present invention, the process of picking up the plasma emission is directed toward the central portion under the process conditions where the emission intensity of the central portion is relatively strong according to various distributions of the emission intensity due to the plasma emission. When the light emission intensity of the part is relatively high, the direction of picking up the plasma light emission is directed toward the outer peripheral part, and the end point can be determined more widely than when the light emission pickup is fixed.

  According to the semiconductor manufacturing apparatus of the present invention, it is not necessary to provide a large number of light-emitting pickup means, and the pickup direction and position are variable. Therefore, there is an advantage that the end point determination by the optimum pickup for each process condition can be realized at low cost.

FIG. 1 is a block diagram showing an example of a conventional semiconductor manufacturing apparatus. FIG. 2 is a block diagram showing an embodiment of the semiconductor manufacturing apparatus of the present invention. FIG. 3 is a flowchart showing an embodiment of the control method of the semiconductor manufacturing apparatus of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a configuration diagram of a semiconductor manufacturing apparatus according to an embodiment of the present invention. Reference numerals 1 to 16 are the same as those in FIG. Further, the difference from FIG. 1 is that a pickup driving means 111 is provided. The apparatus controller 13 sets a setting signal to the pickup driving means 111 and monitors the monitor signal. When an abnormality of any component device is detected, a predetermined abnormality process is performed.

  FIG. 3 shows a configuration example of the pickup driving means 111. The pickup driving unit 111 includes a motor driver 1111, a stepping motor 1112 with an encoder, and a rotation mechanism 1113.

  The light emitting pickup 11 is mounted on the rotation mechanism 1113, and the rotation angle is controlled by a stepping motor 1112 with an encoder. As described above, the apparatus controller 13 gives a rotation angle setting signal to the motor driver 1111 and monitors the actual rotation angle monitor signal. The motor driver 1111 drives the stepping motor with encoder 1112 and outputs a monitor signal of the actual rotation angle based on the signal from the encoder.

  Here, it is conceivable that the rotation axis of the rotation mechanism is perpendicular to the radial direction of the electrode 7 (semiconductor wafer 9), and the tip of the optical axis of the light emitting pickup 11 is variable from the center of the electrode 7 to the outer periphery. In this way, according to various distributions of the light emission intensity by the plasma, the light emitting pickup is directed toward the center in a relatively strong process condition at the center and toward the outer periphery in a condition where the outer periphery is relatively strong. Compared to the fixed case, the end point can be determined widely.

  In addition, the end point determination can be realized at a lower cost than in the case where the light emitting pickups are fixed at a plurality of positions such as for the central part and the outer peripheral part. In this case, it is conceivable to set the rotation angle of the light emitting pickup 11 for each processing step using the rotation angle setting signal as a recipe parameter described in the background art. Further, it is also conceivable to provide a sample pattern for determining the end point on the semiconductor wafer 9 and determine a rotation angle setting signal according to the position.

1 Chamber 2 Solenoid Coil 3 Solenoid Coil 4 DC Power Supply for Solenoid Coil 5 DC Power Supply for Solenoid Coil 6 Pressure Controller 7 Electrode 8 Electrostatic Adsorption Power Supply 9 High Frequency Bias Power Supply 10 Semiconductor Wafer 11 Light Emission Pickup 12 Emission Spectrometer 13 Device Controller 14 Process Gas flow controller 15 Process gas 16 ECR plasma 111 Pickup drive means 1111 Motor driver 1112 Stepping motor with encoder 1113 Rotating mechanism

Claims (2)

In a semiconductor manufacturing apparatus comprising means for detecting plasma emission of plasma formed in a chamber for processing a semiconductor wafer and determining an end point of the processing,
Have a varying means for varying the direction and position to pick up the plasma emission,
The variable means includes a rotation mechanism to which a light emitting pickup is fixed, and means for driving the rotation mechanism,
A semiconductor manufacturing apparatus , wherein a rotation axis of the rotation mechanism is perpendicular to a radial direction of an electrode on which a semiconductor wafer is placed, and an optical axis tip of the light emitting pickup is variable from a center of the electrode to an outer peripheral portion . In a semiconductor processing method for determining a processing end point by detecting plasma emission by forming a plasma in the chamber to process a semiconductor wafer disposed in the chamber ,
While changing the direction and position of picking up the plasma emission for each processing step,
Depending on the various distributions of the emission intensity due to the plasma emission, the process conditions where the emission intensity at the center is relatively strong are directed toward the center in the process conditions for picking up the plasma emission, and the emission intensity at the outer periphery is relatively strong. A semiconductor processing method characterized in that the direction of picking up the plasma emission is directed toward the outer peripheral portion, and the end point can be determined more widely than when the light emitting pickup is fixed .

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