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

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

Pernille V. Larsen @ Danchip and Berit G. Herstrøm @ Danchip.

==This Table shows the acceptance criteria==

| 1||Patterned flat sample of silicon||Sample material: Patterned silicon substrate.||Depth 100±2 µm

| ||||Trench depth with aspect ratio 1:10 on a 10 µm wide trench||

| 2||Patterned flat sample of silicon.||Sample material:  Patterned silicon substrate.||Depth 91±2 µm

| ||||Trench depth with aspect ratio 1:11 on a 8 µm wide trench||

| 3||Patterned flat sample of silicon||Sample material: Patterned silicon substrate||Depth 85±2 µm

| ||||Trench depth with aspect ratio 1:13 on a 6.4 µm wide trench||

| 4||Patterned flat sample of glass||3D profile of pattern etched down in a quartz sample.||Depth within ±1% from a standard profiler measurement and repeatability (3 successive measurements) within 0.1%

| ||||Pattern size 20 µm x 20 µm, depth 500 nm||

| 5||Flat sample of silicon with thick patterned oxide||Step height of patterned thick (10 µm) oxide on top of a silicon wafer.||Step height must be within ±3% of a SEM profile measurement.

| ||||7 µm deep pattern, trench width 6 µm||

| 6||Flat sample of silicon with thick layer of patterned polymer||Sample material: SU8 on silicon. ||Height 69±2 µm

| ||||Pillar heights of 69 µm with 25 µm between pillar edges||

| 7||Free standing structure||Measure bow due to stress of a membrane.||Membrane bow repeatability of 5 successive measurement within 2%

| ||||Membrane material: Si(2 µm)/SiO2(~1 µm)/Au(50 nm).||

| ||||Membrane size: honey comb structure approximately 150 µm in diameter.||

| ||||Bow < 500 nm||

| 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%

| 9||Narrow trenches and holes ||Sample material: Patterned silicon substrate.||Depth 20±2 µm

| ||||2.5 µm wide trench in silicon with a depth of 20 µm||

| 10||Film thickness measurement of transparent thin film||Transparent thin film thickness of 28 nm SiO2 on Si||SiO2 thickness 28±1 nm

| 11||Measurements of multiple stacks||120 nm nitride on 110 nm oxide on a silicon substrate||Within ±2% on each layer from an ellipsometer measurement.  

| 12||Film thickness measurements of transparent films on small structure||Sample material: Si with 1.5 µm patterned AZ-resist||Within ±1% from a standard profiler measurement.

| ||||Measure thickness of AZ-resist on pillars of 50 µm in diameter||

| 13||Roughness repeatability||Sample material: Si wafer with poly-silicon layer.||Repeatability within 0.2%

| ||||3 successive measurements of the roughness ||

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|100x100px|thumb|center|A1]]

[[image:Sensofar_A2_SEM.jpg|100x100px|thumb|center|A2]]

[[image:Sensofar_A3_SEM.jpg|100x100px|thumb|center|A3]]

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

***Gap: 91µm (the trench depth)

*Light souce: increased gain and contrast

Sample material: Patterned fused silica.

Standard profiler measurement:335nm

| 1||337.5

| 2||336.5

| 3||334.7

| 4||335.5

| 5||339.2

| 6||337.2

| 7||334.2

| 8||335.5

| 9||341.1

| 10||344.4

|Average depth||336.58

|Repeatability||3% (the bad repeatability was accepted due to the high noise level in the room)

Sample: Flat sample of silicon with thick patterned oxide.

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|100x100px|thumb|center|A5]]

Sample: Free standing structure.  

 

The sample was not as we suspected. There was almost no bow. The membrane looked broken and it did not really make any sense to measure the bow. The measurement we did are shown here: