Specific Process Knowledge/Characterization/Profiler/Optical Profiler (Sensofar) acceptance test: Difference between revisions

The acceptance test was performed in January 2012 by ST Instruments and Sensofar together with  

Pernille V. Larsen@ DTU nanolab and Berit G. Herstrøm @ DTU nanolab.

| [[#Results_of_acceptance_test_no._1,_2_and_3|1]]||Patterned flat sample of silicon||Sample material: Patterned silicon substrate <br/> Trench depth with aspect ratio 1:10 on a 10 µm wide trench||Depth 100±2 µm

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| [[#Results_of_acceptance_test_no._1,_2_and_3|2]]||Patterned flat sample of silicon.||Sample material:  Patterned silicon substrate <br/> Trench depth with aspect ratio 1:11 on a 8 µm wide trench||Depth 91±2 µm

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| [[#Results_of_acceptance_test_no._1,_2_and_3|3]]||Patterned flat sample of silicon||Sample material: Patterned silicon substrate <br/> Trench depth with aspect ratio 1:13 on a 6.4 µm wide trench||Depth 85±2 µm

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| [[#Results_of_acceptance_test_no._4|4]]||Patterned flat sample of glass||3D profile of pattern etched down in a quartz sample. <br/> Pattern size 20 µm x 20 µm, depth 500 nm||Depth within ±1% from a standard profiler measurement and repeatability (3 successive measurements) within 0.1%

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| [[#Results of acceptance test no. 5|5]]||Flat sample of silicon with thick patterned oxide||Step height of patterned thick (10 µm) oxide on top of a silicon wafer. <br/> 7 µm deep pattern, trench width 6 µm||Step height must be within ±3% of a SEM profile measurement.

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| [[#Results of acceptance test no. 6|6]]||Flat sample of silicon with thick layer of patterned polymer||Sample material: SU8 on silicon. <br/> Pillar heights of 69 µm with 25 µm between pillar edges ||Height 69±2 µm

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| [[#Results of acceptance test no. 7|7]]||Free standing structure||Measure bow due to stress of a membrane. <br/> Membrane material: Si(2 µm)/SiO2(~1 µm)/Au(50 nm) <br/> Membrane size: honey comb structure approximately 150 µm in diameter <br/> Bow < 500 nm ||Membrane bow repeatability of 5 successive measurement within 2%

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| [[#Results of acceptance test no. 8|8]]||Stitching of large area||Stitching 4 mm x 4 mm on same sample as in 7. The area consists of many closed packed honey comb formed membranes.||Membrane bow must the same as on 7 within 2%

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| [[#Results of acceptance test no. 9|9]]||Narrow trenches and holes ||Sample material: Patterned silicon substrate <br/> 2.5 µm wide trench in silicon with a depth of 20 µm||Depth 20±2 µm

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| [[#Results of acceptance test no. 10|10]]||Film thickness measurement of transparent thin film||Transparent thin film thickness of 28 nm SiO2 on Si||SiO2 thickness 28±1 nm

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| [[#Results of acceptance test no. 12|12]]||Film thickness measurements of transparent films on small structure||Sample material: Si with 1.5 µm patterned AZ-resist <br/> Measure thickness of AZ-resist on pillars of 50 µm in diameter||Within ±1% from a standard profiler measurement.

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| [[#Results of acceptance test no. 13|13]]||Roughness repeatability||Sample material: Si wafer with poly-silicon layer <br/> 3 successive measurements of the roughness ||Repeatability within 0.2%

Acceptance criteria: Depth 100±2 µm, 91±2µm and 85±2µm. The SEM profile images of the three trenches are shown here:

[[image:Sensofar_A1_SEM.jpg|200x200px|thumb|center|A1]]

[[image:Sensofar_A2_SEM.jpg|200x200px|thumb|center|A2]]

[[image:Sensofar_A3_SEM.jpg|200x200px|thumb|center|A3]]

====Settings for methode no. 1 for test no. 1, 2 and 3: confocal====

***Gap: 91µm (<- choose the trench depth)

*Light source: increased gain and contrast

Sample material: Patterned flat sample of glass

Standard profiler measurement:335 nm

| 1||337.5||347.9||341.1

| 2||336.5||333.9||340.4

| 3||334.7||341.5||337.2

| 4||335.5||343.2||330.8

| 5||339.2||347.7||339.0

| 6||337.2||345.4||340.0

| 7||334.2||341.8||338.8

| 8||335.5||337.9||339.8

| 9||341.1||342.1||334.6

| 10||344.4||335.9||336.4

|Average depth||337.58||341.73||337.82

|Repeatability||3.0% (the bad repeatability was accepted due to the high noise level in the room)||4.1%||3.0%

Sample: Flat sample of silicon with thick patterned oxide (APOX).

Measurement: Step height of patterned thick (10 µm) oxide on top of a silicon wafer. The pattern is aprox. 7µm thick.

[[Image:Sensofar_A5_SEM.jpg|200x200px|thumb|center|A5]]

Two different setting were tried out, the second was the most successful:

[[image:Sensofar_A9_SEM.jpg|200x200px|thumb|center|SEM profile image of structure]]

Acceptance criteria: SiO2 thickness 28±1 nm  

Sample: 120 nm nitride on 110 nm oxide on a silicon substrate

Measurement: Measurements of multiple stacks

Measurement: Film thickness measurements of transparent films on small structure

Acceptance criteria: Within ±1% from a standard profiler measurement.

Note: Because the surface roughness of the sample was very low and the noise/vibration level too high we could not obtain the specified repeatability.

*The repeatability over 10 measurements was 34%