Problem sts SNF 2008-08-04 08:55:52: Details of Mary Calarrudo's runs ....

[shott at snf.stanford.edu]

Here are the details of Mary Calarrudos runs done with wafers at the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock wafer positions.
12 o'clock wafer:
	T: 274
	C: 278
	F: 273
	L: 274
	R: 270
3 o'clock wafer:
	T: 240
	C: 246
	F: 254
	L: 254
	R: 239
6 o'clock wafer:
	T: 254
	C: 239
	F: 250
	L: 244
	R: 238
9 o'oclock wafer:
	T: 246
	C: 251
	F: 259
	L: 245
	R: 255
In short, the 12 oclock position is noticeably thicker.  And, as Jeannier noted, the overall deposition rate has fallen.  Mary had to increase her depostion time by nearly 25% to get the nominal 250 A oxide thickness.
Do we have a temperature uniformity problem?  Or a gas distripbution problem?
Thanks,
John