What is claimed is:
1. A method for plasma etching a trench in a semiconductor substrate to reduce scalloping of the trench, comprising:
applying a plurality of processing cycles to the substrate, where each cycle comprises a plasma etch period and a plasma deposition period; and
pulsing a substrate bias power during the plasma etch period.
2. The method of claim 1 wherein the trench has a width between 1 to 20 m and an aspect ratio of about 5 to 50.
3. The method of claim 1 wherein the trench has scallops having a peak-to-valley size that is less than 100 nm.
4. The method of claim 1 wherein the plasma etch period has a duration between 1 and 40 seconds.
5. The method of claim 1 wherein the plasma etch period comprises a plasma etch process that uses an etchant gas comprising SF6.
6. The method of claim 1 wherein the plasma deposition period has a duration between 1 and 20 seconds.
7. The method of claim 1 wherein the plasma deposition period comprises a plasma process that uses at least one of a fluorocarbon gas and a hydrofluorocarbon gas.
8. The method of claim 7 wherein the fluorocarbon gas comprises C4F8.
9. The method of claim 7 wherein the hydrofluorocarbon gas comprises CHF3.
10. The method of claim 1 wherein the pulsing step further comprises:
applying the substrate bias power between 1 and 30 milliseconds at a duty cycle of between 10 and 90%.
11. The method of claim 1 wherein the pulsing step further comprises:
applying the substrate bias power for about 6 milliseconds at a duty cycle of about 33%.
12. The method of claim 1 wherein a source power is continuously applied to the plasma while the substrate bias power is pulsed.
13. The method of claim 12 wherein the source power has a frequency of about 12.56 MHz and the substrate bias power has a frequency of about 400 KHz.
14. A computer-readable medium including software that, when executed by a processor, performs a method that causes an etch reactor to etch a trench in a semiconductor substrate to reduce scalloping of the trench, comprising:
applying a plurality of processing cycles to the substrate, where each cycle comprises a plasma etch period and a plasma deposition period; and
pulsing a substrate bias power during the plasma etch period.
15. The computer-readable medium of claim 14 wherein the trench has a width between 1 to 20 m and an aspect ratio of about 5 to 50.
16. The computer readable medium of claim 14 wherein the trench has scallops having a peak-to-valley size that is less than 100 nm.
17. The computer-readable medium of claim 14 wherein the plasma etch period has a duration between 1 and 40 seconds.
18. The computer-readable medium of claim 14 wherein the plasma etch period comprises a plasma etch process that uses an etchant gas comprising SF6.
19. The computer-readable medium of claim 14 wherein the plasma deposition period has a duration between 1 and 20 seconds.
20. The computer-readable medium of claim 14 wherein the plasma deposition period comprises a plasma process that uses at least one of a fluorocarbon gas and a hydrofluorocarbon gas.
21. The computer-readable medium of claim 20 wherein the fluorocarbon gas comprises C4F8.
22. The computer-readable medium of claim 20 wherein the hydrofluorocarbon gas comprises CHF3.
23. The computer-readable medium of claim 14 wherein the pulsing step further comprises:
applying the substrate bias power between 1 and 30 milliseconds at a duty cycle of between 10 and 90%.
24. The computer-readable medium of claim 14 wherein the pulsing step further comprises:
applying the substrate bias power for about 6 milliseconds at a duty cycle of about 33%.
25. The method of claim 14 wherein a source power is continuously applied to the plasma while the substrate bias power is pulsed.
26. The method of claim 14 wherein the source power has a frequency of about 12.56 MHz and the substrate bias power has a frequency of about 400 KHz.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A computer-readable medium encoded with a program of instructions executable by a computer to perform a method for reading a two-dimensional code with digital information expressed by data marks displayed on a plurality of cells arrayed two-dimensionally, comprising:
detecting from an image data containing the two-dimensional code, an image pattern that is distinguished from surrounding cells by verifying an image on the image data with a verification pattern, the detected image pattern includes the image of one or more data marks and each data mark is surrounded by a blank area in each cell, wherein the detecting of the image pattern includes:
verifying the image on the image data with a verification pattern while scanning the image data; and
determining the verified image according to a determining formula, and wherein:
the verification of the image on the image data is performed using a verification pattern consisting of at least two image areas defined according to assumed pixel tones; and
the determining of the image on the image data is performed by assigning pixel tone values calculated in correspondence to each of the image areas of the verification pattern in the determining formula.
2. The computer-readable medium encoded with a program of instructions executable by a computer to perform a method for reading a two-dimensional code with digital information expressed by data marks displayed on a plurality of cells arrayed two-dimensionally, comprising:
detecting from an image data containing the two-dimensional code, an image pattern that is distinguished from surrounding cells by verifying an image on the image data with a verification pattern, the detected image pattern includes the image of one or more data marks and each data mark is surrounded by a blank area in each cell, wherein the detecting of the image pattern includes:
verifying the image on the image data with a verification pattern while scanning the image data and
determining the verified image according to a determining formula;
calculating positions of cells that exist outside of the verified image area using a detected position of the verified image, the verified image including the data mark image;
determining a display of the cells on the calculated position; and
decoding digital information expressed as the two-dimensional code based upon the determined display of the cells.
3. A computer-readable medium encoded with a program of instructions executable by a computer to perform a method for reading a two-dimensional code with digital information expressed by data marks displayed on a plurality of cells arrayed two-dimensionally, comprising:
detecting from a colored image data containing the two-dimensional code consisting of pixels each having a plurality of color components, an image pattern that is distinguished from surrounding cells by verifying an image on the colored image data with a verification pattern for each of the plurality of color components of each pixel, wherein the detected image pattern includes the image of one or more data marks, wherein the detecting of the image pattern includes:
verifying the image on the colored image data with a verification pattern while scanning the colored image data and
determining the verified image according to a determining formula, and wherein:
the verification of the image on the colored image data is performed using a verification pattern consisting of at least two image areas defined according to assumed pixel tones; and
the determining of the image on the colored image data is performed by assigning pixel tone values calculated in correspondence to each of the image areas of the verification pattern in the determining formula.
4. A two-dimensional code, comprising:
digital information expressed by data marks on a plurality of cells arrayed two-dimensionally, wherein the data marks on each cell are displayed in layers of a plurality of color components of an output device, with each data mark surrounded by a blank area where none of the plurality of color components of the output device is output, wherein the displaying of the data marks includes:
separating data rows that constitute the digital information by corresponding said data rows to the plurality of color components of the output device;
determining an arrangement of data marks placed on the cells for each of the separated data rows; and
displaying the data marks in layers of the plurality of color components of the output device in the determined arrangement.
5. The two-dimensional code of claim 4, wherein all of the data marks on each cell further comprise an image pattern with a specific shape and size, and are displayed by coinciding marked areas of all of the color components used for display.
6. The two-dimensional code of claim 4, wherein the data marks comprise an image pattern with a specific shape and size, and the distance of the blank area between two consecutively displayed data marks is between 30% and 80% the width of the data marks.
7. The two-dimensional code of claim 4, wherein the data marks further comprise an image pattern with a specific shape and size, the distance of the blank area between two consecutively displayed data marks is greater than or equal to 127 micrometers.
8. A program of instructions executable by a computer to perform a method for reading a two-dimensional code with digital information expressed by data marks displayed on a plurality of cells arrayed two-dimensionally, the program of instructions comprising:
detecting an image pattern displayed on a specific position by verifying an image on an image data containing the two-dimensional code with a verification pattern; and
obtaining image information from the image of the detected image pattern to use the image information to determine how the cells are displayed, wherein the data marks are displayed with a specific image pattern surrounded by a blank area on each cell,
wherein the image information is obtained from an image of one or more reference marks displayed in the same shape and size as the data marks,
wherein the obtained image information include a value obtained by statistically processing values of pixel tones of a plurality of pixels that constitute each of the image areas in at least two image areas set accordingly to assumed pixel tones.