These etch rates were performed at SNF on films that were processed here. Etch rates are listed in units of angstroms per minute and represent only approximate values. Note that etch rates are dependent on etchant temperature, age, and history, as well as conditions of film growth or deposition.

 

	6:1 Buff HF	20:1 Buff HF	50:1 HF	10:1 HF	Hot Phos.	H2O2	Al etch	Pad Etch	Freckle Etch
Thermal Oxide	910	300	50	280	<10	---	<10	385	73
LTO Undensified	2900	740	300(a)	920	<10	---	<10	2370	459
4% Undensified	4340	1000	350	2000	16	---	<10	4278	2530
8% Undensified	6000	1650	600	3300	30	---	<10	5561	2970
LTO Densified	1400	400	87	715	<10	---	<10	642	91
4% Densified	1625	490	90	1460	<10	---	---	1560	1355
8% Densified	2900	725	290	1500	<10	---	<10	3120	2385
Std Nitride	<10	<10	<10	36	35	---	---	*	43
Low Stress Nitride	<10	<10	<10	40	32	---	---	**	148
Undoped Poly	---	---	---	---	<10	---	<10	---	265

*For the Nitride wafers, when a 1600A stress sample was used 68A were stripped off in the first minute and 4A after that. However, when a 300A sample was used, 8A were removed in the first minute and each additional minute thereafter.

**Low Stress Nitride in Pad etch 337A in the first minute and 4A thereafter.

***Hot Phosphorus was 152C

****Aluminum Etch was 40C

(a)Correction by Brian Greene 6/14/01