OxyNitride Characterization
This characterization focused on varying the percent of NO2. All other
parameters were maintained constant.
This is the recipe:
Gas1 (NH3): 2.5%
Gas2 (SiH4) : 95%
Gas3 (NO2) : 2.5-25%
Pressure : 900 mTorr
Power : 100 W
Temp : 250 deg
Note: This recipe is no longer valid due to MFC changes. Visit the PECVD Deposition page for details.
By varying the amount of NO2(Nitrous Oxide) we can change the index of
refraction. The effects of the condition of the chamber on the index of
refraction of the OxyNitride are unknown. Future characterization would be
necessary to determine that.
The deposition rate increases as NO2 increases.
The index of refraction and deposition thickness were found using the
ellipsometer.
Summary of Data:
|
Wafer |
Gas1 %NH3 |
Gas2 %SiH4 |
Gas3 %NO2 |
Time (min) |
p1 |
a1 |
p2 |
a2 |
δ |
Φ |
Thickness |
Index of Ref. |
|
1 |
2.5 |
95 |
5 |
10 |
103.3 |
35.3 |
193.2 |
146.3 |
63.5 |
34.4999 |
725.06 |
1.7532 |
|
2 |
2.5 |
95 |
10 |
10 |
116.1 |
64.6 |
210 |
115.9 |
33.9 |
64.34999 |
1086.46 |
1.6572 |
|
3 |
2.5 |
95 |
10 |
5 |
95.1 |
28.1 |
185.3 |
152.6 |
79.5999 |
27.74999 |
598.87 |
1.6238 |
|
4 |
2.5 |
95 |
2.5 |
5 |
81.8 |
17 |
171.88 |
163.4 |
106.3999 |
16.8 |
282.14 |
1.7889 |
|
5 |
2.5 |
95 |
5 |
5 |
86.4 |
19.8 |
176.4 |
161.8 |
97.2 |
18.999 |
344.81 |
1.7854 |
|
6 |
2.5 |
95 |
15 |
5 |
98.9 |
35.4 |
187.9 |
143.1 |
73.2 |
35.149999 |
796.99 |
1.5748 |
|
7 |
2.5 |
95 |
20 |
5 |
96 |
31 |
186.4 |
144.6 |
77.6 |
33.1999 |
780.8 |
1.5197 |
|
8 |
2.5 |
95 |
25 |
5 |
95.3 |
37.4 |
185.4 |
143.2 |
79.3 |
37.1 |
916.52 |
1.4608 |
|
9 |
2.5 |
95 |
7.5 |
5 |
90.8 |
23 |
180.1 |
157.4 |
89.0999 |
22.8 |
455.15 |
1.6569 |
|
10 |
2.5 |
95 |
12.5 |
5 |
96.7 |
31 |
186.7 |
149.6 |
76.6 |
30.6999 |
685.39 |
1.5919 |
Using a trend line we can estimate the recipe for desired indices of
refraction:
|
Desired Index |
Percent NO2 |
Dep. Rate Ǻ/Min |
|
1.44 |
24.8% |
194 |
|
1.45 |
24.1% |
190 |
|
1.46 |
23.4% |
186 |
|
1.47 |
22.8% |
182 |
|
1.48 |
22.1% |
178 |
|
1.49 |
21.4% |
174 |
|
1.5 |
20.7% |
171 |
|
1.51 |
20.0% |
167 |
|
1.52 |
19.4% |
163 |
|
1.53 |
18.7% |
159 |
|
1.54 |
18.0% |
155 |
|
1.55 |
17.3% |
151 |
|
1.56 |
16.6% |
147 |
|
1.57 |
16.0% |
143 |
|
1.58 |
15.3% |
139 |
|
1.59 |
14.6% |
135 |
|
1.6 |
13.9% |
131 |
|
1.61 |
13.2% |
128 |
|
1.62 |
12.6% |
124 |
|
1.63 |
11.9% |
120 |
|
1.64 |
11.2% |
116 |
|
1.65 |
10.5% |
112 |
|
1.66 |
9.8% |
108 |
|
1.67 |
9.2% |
104 |
|
1.68 |
8.5% |
100 |
|
1.69 |
7.8% |
96 |
|
1.7 |
7.1% |
92 |
|
1.71 |
6.4% |
88 |
|
1.72 |
5.8% |
85 |
|
1.73 |
5.1% |
81 |
|
1.74 |
4.4% |
77 |
|
1.75 |
3.7% |
73 |
|
1.76 |
3.0% |
69 |
