materials ALD films
Figure 6,resistivity of platinum film on various oxides by plasma-ALD at 300o
C vs precursor
dose-time.It is clear that the order of resistivity of Pt film grown on oxides is Si/SiO2> Si/Al2O3> Si/HfO2
grown on Si by plasma ALD is bigger than that of thermal ALD at same cycle numbers.
Table 2 gives a short summary of Pt particle-size at 50 and 100 cycles, respectively, and the process
data of Pt films on the surface of Si, SiO2, Al2O3 and HfO2 deposited at 300°C by thermal and remote plasma ALD for 500 cycles. The growth rate and
resistivity of Pt plasma-ALD layers on various oxides is shown in Figure 9.
HfO2 shows the highest growth rate and the lowest resistivity of them. It is believed that surface
functionalisation by plasma-ALD and rich-absorbed oxygen radicals on HfO2 surface are the reasons.
From Fig.3 and Fig.5 we have found that the Pt films deposited on Si (100) substrates showed a Pt nucleation delay of 70 cycles and 20 cycles grown by thermal ALD and plasma-ALD before the Pt ALD process goes to a linear growth. Table 2 shows Pt particles increase in size with the number of Pt ALD cycles performed and it is also clear that the Pt particles grown by plasma-ALD are bigger than those by thermal ALD. It is believed that surface functionalisation by plasma-ALD plays a important
role to shorten the nucleation delay. In the O2 plasma, O radicals are created, leading to three effects on the Pt growth by reducing the nucleation delay:
1) providing active atomic O to the surface;
Figure 7,AES of 30nm Pt film grown by plasma-ALD
Left: Ex-situ M2000 ellipsometer with motorized X-Y mapping stage at Oxford Instruments Right: the M2000 ellipsometer mounted in-situ on the FlexAL tool in OIPT’s laboratory
Issue III 2012
www.siliconsemiconductor.net 17
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40