Abstract:
An embodiment of a semiconductor manufacturing device includes a chamber to perform a predetermined semiconductor process, a light source to emit light into the chamber, a light receiver to sense scattered light emitted from the light source and to measure an intensity of the scattered light, a first controller to compare the measured intensity of the scattered light with a preset reference value, and a second controller to determine whether to perform the predetermined semiconductor process based on the intensity of the scattered light. An embodiment of the particle monitoring method includes emitting laser light into a process chamber simultaneously with performing a semiconductor process, measuring an intensity of a scattered light after being emitted, comparing the measured intensity of the scattered light with a preset reference value, and interlocking the semiconductor process when the measured intensity of the scattered light is larger than the preset reference value.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application hereby claims priority under 35 U.S.C. § 119 to Korean Patent Application 2005-64413 filed on Jul. 15, 2005, of which the entire contents are hereby incorporated herein by reference.  
       BACKGROUND  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a semiconductor manufacturing device, and more particularly, to a semiconductor manufacturing device and a particle monitoring method, which can detect the existence of particles in a process chamber.  
         [0004]     2. Description of the Related Art  
         [0005]     In the semiconductor industry, increasing the diameter of a wafer tends to reduce manufacturing costs while increasing production output. For example, wafer diameters have recently increased from 200 mm to  300  mm. Unfortunately, a downside to increasing surface areas of the semiconductor wafers is an increased likelihood of foreign particles disposed on the wafer. Because of the small features of a typical semiconductor wafer, even a very small particle can render the complete wafer defective and inoperable. Thus, there is a push in the industry for increasingly high-performance clean room environments. With this, there is a need for novel and better ways to detect these particles.  
       SUMMARY  
       [0006]     Embodiments herein provide a semiconductor manufacturing device and a particle monitoring method, which can detect the existence of particles on a wafer.  
         [0007]     Embodiments also provide a semiconductor manufacturing device and a particle monitoring method, which can detect, by laser light, particles attached onto a wafer.  
         [0008]     Embodiments provide semiconductor manufacturing devices including: a chamber used to perform a predetermined semiconductor process; a light source emitting light into the chamber; a light receiver sensing a scattered light emitted from the light source and measuring an intensity value of the scattered light; a first controller comparing the measured intensity of the scattered light with a preset reference value; and a second controller determining whether to perform the predetermined semiconductor process based on the intensity of the scattered light.  
         [0009]     In some embodiments, semiconductor manufacturing devices include: a process chamber used to perform a predetermined semiconductor process; a laser light source disposed at the topside of the chamber to emit light into the process chamber in a substantially vertical direction; a light receiver disposed at one lateral side of the chamber to sense a scattered light emitted from the laser light source and to measure an intensity value of the scattered light; a first controller electrically connected to the light receiver to compare the intensity of the scattered light with a preset reference value; and a second controller electrically connected to the first controller to continuously perform the predetermined semiconductor process when the intensity of the scattered light is equal to or smaller than the present reference value and to interlock the predetermined semiconductor process when the intensity of the scattered light is larger than the preset reference value.  
         [0010]     In further embodiments, semiconductor manufacturing devices include: a chamber used to perform a predetermined semiconductor process; a light source emitting light into the chamber; a light receiver sensing a incident light emitted from the light source and measuring an intensity of the incident light; a first controller comparing the measured intensity of the incident light with a preset reference value; and a second controller determining whether to perform the predetermined semiconductor process based on the intensity of the incident light.  
         [0011]     In still further embodiments, semiconductor manufacturing devices include: a process chamber used to perform a predetermined semiconductor process; a laser light source disposed at one lateral side of the process chamber to emit light into the process chamber in a substantially horizontal direction; a light receiver disposed at the other lateral side of the process chamber to face the laser light source, to sense a incident light emitted from the laser light source, and to measure an intensity of the incident light; a first controller electrically connected to the light receiver to compare the intensity of the incident light with a preset reference value; and a second controller electrically connected to the first controller to continuously perform the predetermined semiconductor process when the intensity of the incident light is equal to or larger than the present reference value and to interlock the predetermined semiconductor process when the intensity of the incident light is smaller than the preset reference value.  
         [0012]     In yet further embodiments, particle monitoring methods include: emitting laser light into a process chamber simultaneously with performing a semiconductor process; measuring an intensity of light scattered after being emitted; comparing the measured intensity of the scattered light with a preset reference value; and interlocking the semiconductor process when the measured intensity of the scattered light is larger than the preset reference value.  
         [0013]     In still yet further embodiments, particle monitoring methods include: emitting laser light into a process chamber simultaneously with performing a semiconductor process; measuring an intensity of the laser light emitted into the process chamber; comparing the measured intensity of the laser light with a preset reference value; and interlocking the semiconductor process when the measured intensity of the laser light is smaller than the preset reference value.  
         [0014]     The laser light source and the light receiver may be installed in the chamber of the semiconductor manufacturing device and the reflection or loss rate of the laser light may be measured to verify in real time whether or not particles exist in the chamber or on the wafer. Accordingly, the process failure can be prevented to minimize the damage or loss of the wafer. In addition, it is possible to control the process conditions and to predict the time of preventive management. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principle of the invention. In the drawings:  
         [0016]      FIG. 1  is a cross-sectional view of a semiconductor manufacturing device according to a first embodiment;  
         [0017]      FIG. 2  is a flowchart illustrating a particle monitoring method using the semiconductor manufacturing device according to the first embodiment;  
         [0018]      FIG. 3  is a cross-sectional view of a semiconductor manufacturing device according to a first embodiment; and  
         [0019]      FIG. 4  is a flowchart illustrating a particle monitoring method using the semiconductor manufacturing device according to the first embodiment. 
     
    
     DETAILED DESCRIPTION  
       [0020]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. However, the present invention is not limited to the embodiments illustrated herein after, and the embodiments herein are rather introduced to provide easy and complete understanding of the scope and spirit of the present invention.  
         [0021]     Semiconductor manufacturing devices and particle monitoring methods according to the embodiments will now be described in detail with reference to  FIGS. 1 through 4 .  
       Embodiment 1  
       [0022]      FIG. 1  illustrates a case where light scattered by particles in the semiconductor manufacturing device may be detected in a direction different from that of an incident light. The incident light may be laser light.  
         [0023]     Referring to the figure, the semiconductor manufacturing device  100  includes a process chamber  110  in which a semiconductor manufacturing process may be performed. A chuck  120  may be installed at an inner bottom side of the process chamber  110  to provide a place where a wafer W is mounted. The chuck  120  may be an electrostatic chuck (ESC) that stably adheres the wafer W thereto by electrostatic force.  
         [0024]     A light source  130  is installed at the topside of the process chamber  110 . Light emitted from the light source  130  may be radiated toward the wafer W substantially vertically, as shown. A light receiver  140  may be disposed at one lateral side of the process chamber  110 . In a preferred embodiment, the light receiver  140  is elevated above the surface of the wafer chuck  120 . The light receiver  140  may receive light scattered by particles  190  and then may convert the received light into an electrical signal that is responsive to the intensity of the scattered light. It is preferable that the conversion into the electrical signal is linearly proportional to the intensity of the scattered light. Alternatively, the conversion may be nonlinear if the strength of the electrical signal is a one-to-one correspondence with the intensity of the scattered light. The light receiver  140  may be any photoelectric converter such as a charge-coupled device and a photomultiplier, to name a few examples.  
         [0025]     The electrical signal converted from the scattered light may be input into a controller  150 . An allowed maximum intensity of the scattered light may be preset in the controller  150 . This allowed maximum intensity acts as a reference value for determining the existence and allowed density or size of particles in the process chamber  10  floating between the light source  130  and wafer W. The controller  150  may compare the strength of the input electrical signal or the measured intensity of the scattered light with the reference value. When the measured intensity of the scattered light is equal to or smaller than the reference value, the controller  150  may determine that no particle exists in the process chamber  110 , or that particles exist only to the extent that they do not affect the manufacturing process. On the contrary, when the measured intensity of the scattered light is larger than the reference value, the controller  150  may determine that particles exist to the extent that they adversely affect the manufacturing process.  
         [0026]     The controller  150  is electrically connected to a process controller  160  that controls the overall manufacturing process. When the controller  150  determines that particles exist to the extent that they may adversely affect the manufacturing process, the process controller  160  may in turn interlock the manufacturing process. Thereafter, the process controller  160  performs a subsequent process such as a cleaning process.  
         [0027]     An example of an operation of the above semiconductor manufacturing device embodiment will now be described in detail with reference to  FIGS. 1 and 2 .  
         [0028]     Referring to  FIGS. 1 and 2 , it is assumed that a wafer to be processed is loaded onto the chuck  120  and then a specific semiconductor manufacturing process, for example, a chemical vapor deposition (CVD) process, is performed in the process chamber  110 .  
         [0029]     Process gas is supplied from a shower head  180  disposed over the process chamber  110 , to perform the CVD process in block  200 . At this point, light, preferably laser light (e.g., continuous or pulsed) from the light source  130  is radiated toward the wafer disposed on the chuck  120  and the intensity of the scattered light is measured in block  210 .  
         [0030]     When the process chamber  10  has favorable internal conditions and few or no particles are generated therein, the incident light from the light source  130  is barely, if at all, scattered. The measured value of the scattered light is compared with a reference value in query block  220  The strength of the electrical signal transferred from the light receiver  140  to the controller  150  or the measured intensity of the scattered light may be equal to or smaller than the reference value. In this case, the process controller  160  does not interlock the ongoing CVD process and the process therefore continues in block  230  until completion or until subsequent particle detection processes determine an adverse result.  
         [0031]     On the contrary, when particles  190  are generated considerably in the process chamber  110 , light scattered by the particles  190  is sensed by the light receiver  140 . The light receiver  140  converts the sensed light into an electrical signal. The controller  150  compares the strength of the electrical signal or the measured intensity of the scattered light with the reference value in query block  220  to determine whether the measured intensity of the scattered light is smaller than the reference value. When the measured intensity of the scattered light is larger than the reference value, the process controller  160  interlocks the ongoing CVD process in block  240 . Thereafter, the wafer where particles are generated is unloaded from the process chamber  110  and then discarded or cleaned in block  250 . If necessary, cleaning gas is injected into the process chamber  110  to clean the inside of the process chamber  110  and remove the particles  190 . Thereafter, the semiconductor manufacturing process is resumed in block  200 .  
       Embodiment 2  
       [0032]      FIG. 3  illustrates a case where light scattered by particles in the semiconductor manufacturing device is monitored in a direction substantially identical to that of the incident light. Descriptions about the same contents as in  FIG. 1  will be brief or omitted for conciseness, and only the differences from  FIG. 1  will be described in detail.  
         [0033]     Referring to  FIG. 3 , a semiconductor manufacturing device  300  includes a process chamber  310  in which a chuck  320  for mounting a wafer is installed. A light source  330 , which may emit laser light, may be installed at one lateral side of the process chamber  310 , and a light receiver  340  facing the light source  330  may be installed at the other lateral side of the process chamber  310 .  
         [0034]     Light emitted from the light source  330  may be radiated toward the wafer in a substantially horizontal direction. The light receiver  340  may be configured to include a photoelectric converter. The light receiver  340  may receive and convert incident light into an electrical signal. When light scattering is generated by particles  390 , a portion of the incident light is lost to the scattering. In this case, the electrical signal converted from the incident light has a smaller intensity than when no particle exists.  
         [0035]     The electrical signal converted from the incident light may be input into a controller  350 . An allowed minimum intensity value of the incident light may be preset in the controller  350 . This allowed minimum intensity value acts as a reference value for determining the existence of particles in the process chamber  310 . The controller  350  may compare the strength of the input electrical signal or the measured intensity of the incident light with the reference value to determine whether the measured intensity of the incident light is smaller than the reference value. When the measured intensity of the incident light is equal to or larger than the reference value, the controller  350  may determine that no particle exists in the process chamber  310 , or that particles exist only to the extent that they do not affect the manufacturing process. On the contrary, when the measured intensity of the incident light is smaller than the reference value, the controller  350  may determine that the particles exist to the extent that they adversely affect the manufacturing process.  
         [0036]     The controller  350  may be electrically connected to a process controller  360  that controls the overall manufacturing process. When the controller  350  determines that particles exist to the extent that they adversely affect the manufacturing process, the process controller  360  may interlock the manufacturing process. Thereafter, the process controller  360  may perform a subsequent process such as a cleaning process.  
         [0037]     An example of an operation of the above semiconductor manufacturing device embodiment will now be described in detail with reference to  FIGS. 3 and 4 .  
         [0038]     Referring to these figures, it is assumed that a wafer to be processed is loaded onto the chuck  320  and then a specific semiconductor manufacturing process (e.g., a CVD process) is performed in the process chamber  310  in block  400 . Process gas is supplied from a shower head  380  disposed over the process chamber  310 , to perform the CVD process. At this point, light, preferably laser light (e.g., continuous or pulsed) is emitted from the light source  330  toward the light receiver  340  in the substantially horizontal direction and the intensity of light received at detector  340  is measured in block  410 .  
         [0039]     A comparison step occurs within controller  350  of the intensity measured in block  410  with the reference value in query block  420 . When the process chamber  310  has good internal conditions and few or no particles are generated therein, the incident light from the laser light source  330  is only slightly, if at all, scattered, and thus the strength of the electrical signal (or intensity of the incident light) transferred from the light receiver  340  to the controller  350  is equal to or larger than the reference value. In this case, the process controller  360  does not interlock the ongoing CVD process and the process continues in block  430 .  
         [0040]     On the contrary, when particles  390  are generated in the process chamber  310 , a portion of the incident light is scattered by the particles  390 . The light receiver  340  senses and converts the incident light into an electrical signal in block  410 . The controller  350  compares the strength of the electrical signal or the measured intensity of the incident light with the reference value in query block  420  to determine whether the measured intensity of the incident light is smaller than the reference value. When the measured intensity of the incident light is smaller than the reference value, the process controller  360  interlocks the ongoing CVD process in block  440 . Thereafter, the wafer where the particles are generated is unloaded from the process chamber  310  and then discarded or cleaned in block  450 . If necessary, cleaning gas is injected into the process chamber  310  to clean the inside of the process chamber  310  and remove the particles  390 . Thereafter, the semiconductor manufacturing process is resumed.  
         [0041]     As described above, the light source and the light receiver may be installed in the chamber of the semiconductor manufacturing device and the reflection or loss rate of the light may be measured to verify in real time whether particles exist on the wafer. Accordingly, a process failure can be prevented to minimize the damage or loss of the wafer. In addition, it is possible to control the process conditions and to predict the time of preventive management.  
         [0042]     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.