Hopes for the new year
So, was it just a stupid reversal of polarity that took away an additional work from me ? and also ended uo breaking the sample ?
Well, so was it, december 19, I had my LASER ready, dot on the deadline, but the basic diode test showed an open... The top p contacts must have been okay, for it showed a good pad to pad 1 kohm resistance, and naturally the fingers pointed to the back n contact..
Another day polishing the backside, and doing the metal all over again, and in between an extra-cautious cleaning broke the sample, at about 1/5th from one side, a very parallel to the edge cleave at that ...
And today, it all boiled down to reversal of polarity, and I am now left with a "sample of hope" for the new year... yeah, come Jan 2 and I would hopefully have delivered the second successful "mode-lockable" laser, and also, adding on to my credibility as Chris pointed out "Pretty much every wafer you touched, you've got working lasers out of them"
Is that so ?
* I started off with a Broad area Laser using contact aligner- it worked
* Then came the single mode LASER using contact aligner- they worked to the extend that I could make it .. All it took to convince Chris that its time to move onto stepper was to make him sit at the contact aligner, trying to make a 2 um window align to a 3 um mesa..
* Onto the stepper: Laser- 1 and Laser -2, got cruelly messed up by a tube furnace, which happily showed 400 degrees on its reading, but must have been way high for it to almost clean up the polyimide - well... partly my fault because I should have noticed that the damn thing was reading 28 degrees for RT, where as the cleanroom is usually at 18 ....
* Laser-3 --- worked, but then in between I had cleaved it to see the cross section ... but LASERS after all.... Hopefully some of them would be packaged
* LASER-4 : the classic so far... mode-locked... and hopefully the ones which I did not test, would be packaged and "supplied" to others for their measurement
LASER-5 : keeping my fingers crossed.. if it works, I could try using it for a reflective coating on the saturable absorber run
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So, would you give me a 100% :-) ...... atleast definitely better than the yield Chris is said to have (with the ufm etch back of the polyimide) - 10% ... and undoubtebly better than the "BW" semiconductors who are professional fabricators , who ate all the money and send back "mode-lock lasers" which did not even work as diodes ... Must have screwed up polyimide etching part ...
neways, not bad, after all the trauma , after all the TA+MS+newgroup in Spring of 2005.. - phoenix ?? - well, not really... Summer and even to a good extend fall was slow and sluggish.. its only late fall that I seemed to have rediscoeverd my soul.. and how I wish there is no looking back... with laser-5, proposal, and ... well a good take off ...
So, was it just a stupid reversal of polarity that took away an additional work from me ? and also ended uo breaking the sample ?
Well, so was it, december 19, I had my LASER ready, dot on the deadline, but the basic diode test showed an open... The top p contacts must have been okay, for it showed a good pad to pad 1 kohm resistance, and naturally the fingers pointed to the back n contact..
Another day polishing the backside, and doing the metal all over again, and in between an extra-cautious cleaning broke the sample, at about 1/5th from one side, a very parallel to the edge cleave at that ...
And today, it all boiled down to reversal of polarity, and I am now left with a "sample of hope" for the new year... yeah, come Jan 2 and I would hopefully have delivered the second successful "mode-lockable" laser, and also, adding on to my credibility as Chris pointed out "Pretty much every wafer you touched, you've got working lasers out of them"
Is that so ?
* I started off with a Broad area Laser using contact aligner- it worked
* Then came the single mode LASER using contact aligner- they worked to the extend that I could make it .. All it took to convince Chris that its time to move onto stepper was to make him sit at the contact aligner, trying to make a 2 um window align to a 3 um mesa..
* Onto the stepper: Laser- 1 and Laser -2, got cruelly messed up by a tube furnace, which happily showed 400 degrees on its reading, but must have been way high for it to almost clean up the polyimide - well... partly my fault because I should have noticed that the damn thing was reading 28 degrees for RT, where as the cleanroom is usually at 18 ....
* Laser-3 --- worked, but then in between I had cleaved it to see the cross section ... but LASERS after all.... Hopefully some of them would be packaged
* LASER-4 : the classic so far... mode-locked... and hopefully the ones which I did not test, would be packaged and "supplied" to others for their measurement
LASER-5 : keeping my fingers crossed.. if it works, I could try using it for a reflective coating on the saturable absorber run
-------------
So, would you give me a 100% :-) ...... atleast definitely better than the yield Chris is said to have (with the ufm etch back of the polyimide) - 10% ... and undoubtebly better than the "BW" semiconductors who are professional fabricators , who ate all the money and send back "mode-lock lasers" which did not even work as diodes ... Must have screwed up polyimide etching part ...
neways, not bad, after all the trauma , after all the TA+MS+newgroup in Spring of 2005.. - phoenix ?? - well, not really... Summer and even to a good extend fall was slow and sluggish.. its only late fall that I seemed to have rediscoeverd my soul.. and how I wish there is no looking back... with laser-5, proposal, and ... well a good take off ...
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