| AVS 65th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Division Poster Session |
| Presenter: | Camila Ruiz, Plasma Nanotechnology Research Center, UNICAMP, Brazil |
| Authors: | C.S. Ruiz, Plasma Nanotechnology Research Center, UNICAMP, Brazil J.A. Diniz, Plasma Nanotechnology Research Center, University of Campinas, Brazil A.M. Rosa, Plasma Nanotechnology Research Center, University of Campinas, Brazil |
| Correspondent: | Click to Email |
TiN and Al films were used as hard mask (HM) materials in Si etching using a high-density inductively coupled plasma (ICP) reactor for silicon micro-channel (SiMC) (with depth > 1 µm) fabrication. The main proposal on this research is define a best hard mask (HM) for silicon micro-channel (SiMC) fabrication using ICP (Inductively Coupled Plasma) etching process. In addition, there are some important properties for hard mask should achieve, such as high mechanical performance and etch resistance to support the high process conditions. The TiN and Al films were deposited on silicon substrate by sputtering. Table 1 presents the obtained samples, with the thickness values and whether the annealing was performed or not.
| Table 1. The obtained samples and the Hard Mask (HM) conditions
| Table 2 The used ICP parameters (fixed conditions: P=30mTorr, 450WICP, 100WRIE)
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The ICP processes to fabricate the silicon micro-channels (SiMC) and to characterize the mask resistance under the plasma etching were carried out using these fixed parameters as table 2. Two different gas mixtures were used for etching steps without the environment changing: SF6+Ar, and SF6+N2 for 10, 20 and 30 minutes were employed. Two sequences of gas mixtures were used for etching steps in cycles with the gas environment changing: the first cycle was: 20 seconds SF6+Ar, and in the sequence, 20 seconds, with C3F8+Ar; the second cycle was: 20 seconds with SF6+N2, and in the sequence, 20 seconds, with 48sccm of C3F8+N2 for 20 minutes. The steps in cycles with different gas environments were based on Bosch process [1,2]. Usually, the Bosch process is performed using the cycles based on one sequence with SF6/Ar gas mixture, with C4F8/Ar. In this work, we have used C3F8 gas, instead of traditional C4F8. Table 2 shows the conditions of ICP etching processes. The TiN hard masks have presented high resistance to etching process. However, the 100 nm Al films did not present high resistance, because the sputtering mechanism can occur. The 500 nm thick layers (samples E and F, Table 1), have presented the high resistance to etching process.