Exposure device and method for producing a mask for use in the device

• US 6,124,922 A
• Filed: 01/13/1997
• Issued: 09/26/2000
• Est. Priority Date: 01/17/1996
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sentoku, Koichi
• Primary Examiner(s): Lee, Eddie C.
• Assistant Examiner(s): NGUYEN, HUNG
• Application Number:
  US08/782,382
• Time in Patent Office: 1,352 Days
• Field of Search: 355/53, 355/67, 355/77, 355/72, 356/400, 356/401, 250/548
• US Class Current: 355/53
• CPC Class Codes: G03F 9/7003 Alignment type or strategy, e.g. leveling, global alignment
• CPC Class Codes: G03F 9/7046 Strategy, e.g. mark, sensor or wavelength selection

Abstract

An exposure device in which relative alignment between first and second objects is conducted by using an alignment and in which a pattern on the first object is exposed onto the second object to form the pattern on the first object onto the second object. The exposure device includes a mark detecting device for detecting an actual position of the alignment and for producing a detection signal, a moving device for moving the first and second objects relative to each other to perform alignment of the first and second objects and a control device for storing a positional error of the alignment mark generated when the alignment mark is formed on the second object and for controlling the alignment of the first and second objects by the moving device in accordance with the positional error and the detection signal obtained by the mark detecting device. Also disclosed is a mask producing method, an exposure method and semiconductor device producing methods that include related features.

Claims

1. A mask producing method in which relative alignment between a mask and a wafer is effected by using an alignment mark and in which a pattern on the mask is exposed onto the wafer to form the pattern on the mask onto the wafer, said method comprising the steps of:

obtaining exposure distortion alignment error data when the pattern on the mask is exposed onto the wafer, wherein the exposure distortion alignment error data is obtained on a basis of information regarding exposure conditions at the time of the pattern exposure; and

thereafter, forming the alignment mark onto the mask at a position obtained by correcting a positional error on the basis of the obtained exposure distortion alignment error data.

2. An exposure method in which relative alignment between a mask and a wafer is effected by using an alignment mark and in which a pattern on the mask is exposed onto the wafer to form the pattern on the mask onto the wafer, said method comprising the steps of:

obtaining exposure distortion alignment error data when the pattern on the mask is exposed onto the wafer, wherein the exposure distortion alignment error data is obtained on a basis of information regarding exposure conditions at the time of the exposure;

thereafter, forming the alignment mark onto the mask at a position obtained by correcting a positional error on the basis of the obtained exposure distortion alignment error data;

a mark detecting step for detecting an actual position of the alignment mark; and

performing alignment between the mask and the wafer on the basis of a result of said mark detecting step.

3. An exposure apparatus, including an exposure light source having an optical axis, in which relative alignment of a first object and a second object is conducted by using a plurality of alignment mark patterns formed on the first object and a plurality of alignment marks formed on the second object, in which a mask pattern on the first object is exposed to project the mask pattern onto the second object, and which corrects an alignment error between the first and second objects due to an exposure distortion, said exposure apparatus comprising:

alignment mark detecting means for detecting an actual position of at least one of the plurality of alignment marks formed on the second object and for producing a detection signal;

position detecting means for (i) detecting positional information when the plurality of alignment marks are formed on the second object, the positional information including information relating to a distance between the exposure light source and the first object, a distance between the first and second objects, and the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light, and (ii) producing positional error data including exposure distortion alignment error data based on the detected positional information, the exposure distortion alignment error data representing an amount proportional to the distance between the optical axis of the exposure light and at least one of the plurality of alignment marks formed on the second object;

moving means for moving the first and second objects relative to each other to perform alignment of the first and second objects; and

control means for storing the positional information and the detection signal, and for controlling the alignment of the first and second objects by said moving means in accordance with both the positional error data and the detection signal obtained by said alignment mark detecting means, said control means compensating for the exposure distortion when aligning the first and second objects using the exposure distortion alignment error data.

4. An apparatus according to claim 3, wherein the plurality of alignment marks are formed by projecting a plurality of alignment mark patterns on a third object onto the second object by using said exposure apparatus, and the positional information includes information relating to a distance between the exposure light source and the third object, a distance between the third and second objects, and the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light.

5. An apparatus according to claim 3, wherein said control means controls said moving means to align the first and second objects in accordance with the detection signal, and then controls said moving means to correct the alignment error of the first and second objects in accordance with the positional information including the exposure distortion alignment error data.

6. An apparatus according to claim 3, wherein the exposure distortion alignment error data includes a value obtained when the plurality of alignment marks are formed on the second object by mathematically dividing the distance between the first and second objects by the distance between the exposure light source and the first object and mathematically multiplying by the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light.

7. An apparatus according to claim 3, wherein said control means corrects the detection signal obtained by said alignment mark detecting means by using the positional information, including the exposure distortion alignment error data, to produce a correct ed detection signal, and controls said moving means to effect the alignment of the first and second objects in accordance with the corrected detection signal.

8. An exposure method using an exposure apparatus having an exposure light source with an optical axis, in which relative alignment of a first object and a second object is conducted by using a plurality of alignment mark patterns formed on the first object and a plurality of alignment marks formed on the second object, in which a mask pattern on the first object is exposed to project the mask pattern onto the second object, and which corrects an alignment error between the first and second objects due to an exposure distortion, said exposure method comprising the steps of:

detecting an actual position of at least one of the plurality of alignment marks formed on the second object and producing a detection signal;

detecting positional information when the plurality of alignment marks are formed on the second object, the positional information including information relating to a distance between the exposure light source and the first object, a distance between the first and second objects, and the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light;

producing positional error data including exposure distortion alignment error data based on the detected positional information, the exposure distortion alignment error data representing an amount proportional to the distance between the optical axis of the exposure light and at least one of the plurality of alignment marks formed on the second object;

moving the first and second objects relative to each other to perform alignment of the first and second objects using moving means;

storing the positional information and the detection signal; and

controlling the alignment of the first and second objects by the moving means in accordance with both the positional error data and the detection signal, using the exposure distortion alignment error data to compensate for the exposure distortion when aligning the first and second objects.

9. A method according to claim 8, further comprising forming the plurality of alignment marks by projecting a plurality of alignment mark patterns on a third object onto the second object by using the exposure apparatus, wherein the positional information includes information relating to a distance between the exposure light source and the third object, a distance between the third and second objects, and the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light.

10. A method according to claim 8, wherein said controlling step comprises controlling the moving means to align the first and second objects in accordance with the detection signal, and then controlling the moving means to correct the alignment error of the first and second objects in accordance with the positional information including the exposure distortion alignment error data.

11. A method according to claim 8, wherein the detected exposure distortion alignment error data includes a value obtained when the plurality of alignment marks are formed on the second object by mathematically dividing the distance between the first and second objects by the distance between the exposure light source and the first object and mathematically multiplying by the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light.

12. A method according to claim 8, wherein said controlling step corrects the detection signal using the positional information, including the exposure distortion alignment error data, to produce a corrected detection signal, and controls the moving means to effect the alignment of the first and second objects in accordance with the corrected detection signal.

13. A semiconductor device producing method using an exposure apparatus having an exposure light source with an optical axis, in which relative alignment of a mask and a wafer is conducted by using a plurality of alignment mark patterns formed on the mask and a plurality of alignment marks formed on the wafer, in which a mask pattern on the mask is exposed to project the mask pattern onto the wafer before submitting the wafer to a developing process, and which corrects an alignment error between the mask and wafer due to an exposure distortion, said exposure method comprising the steps of:

detecting an actual position of at least one of the plurality of alignment marks formed on the wafer and then producing a detection signal;

detecting positional information when the plurality of alignment marks are formed on the wafer, the positional information including information relating to a distance between the exposure light source and the mask, a distance between the mask and wafer, and the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light, and producing positional error data including exposure distortion alignment error data based on the detected positional information, the exposure distortion alignment error data representing an amount proportional to the distance between the optical axis of the exposure light and at least one of the plurality of alignment marks formed on the wafer;

moving the mask and wafer relative to each other to perform an alignment of the mask and wafer using moving means;

storing the positional information and the detection signal; and

controlling the alignment of the mask and wafer by said moving means in accordance with both the positional error data and the detection signal, using the exposure distortion alignment error data to compensate for the exposure distortion when aligning the mask and wafer.

14. A method according to claim 13, wherein said controlling step corrects the detection signal using the positional information, including the exposure distortion alignment error data, to produce a corrected detection signal, and controls the moving means to effect the alignment of the first and second objects in accordance with the corrected detection signal.

15. An exposure apparatus, including an exposure light source having an optical axis, in which relative alignment of a first object and a second object is conducted by using a plurality of alignment mark patterns formed on the first object and a plurality of alignment marks formed on the second object, in which a mask pattern on the first object is exposed to project the mask pattern onto the second object, and which corrects an alignment error between the first and second objects due to an exposure distortion, said exposure apparatus comprising:

alignment mark detecting means for detecting an actual position of at least one of the plurality of alignment marks formed on the second object and for producing a detection signal;

position detecting means for (i) detecting positional information when the plurality of alignment marks are formed on the second object, the positional information including information relating to a distance between the exposure light source and the first object, a distance between the first and second objects, and the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light, and (ii) producing positional error data including exposure distortion alignment error data based on the detected positional information, the exposure distortion alignment error data representing an amount proportional to the distance between the optical axis of the exposure light and at least one of the plurality of alignment marks formed on the second object, and includes a value obtained when the plurality of alignment marks are formed on the second object by mathematically dividing the distance between the first and second objects by the distance between the exposure light source and the first object and mathematically multiplying by the distance between at least one of the plurality of alignment mark patterns and the optical axis of the exposure light;

moving means for moving the first and second objects relative to each other to perform an alignment of the first and second objects; and

control means for storing the positional information and the detection signal, and for controlling said moving means to align the first and second objects in accordance with both the positional error data and the detection signal obtained by said alignment mark detecting means.

16. An apparatus according to claim 15, wherein said control means controls said moving means to first align the first and second objects in accordance with the detection signal, and thereafter corrects the alignment error of the first and second objects in accordance with the positional information including the exposure distortion alignment error data using said moving means.