Application of Oxynitrides for Microelectronic Devices and Gas Barriers
- Pp. 285-339 (55)Yung-Hsien Wu and Jia-Hong Huang
As the microelectronic devices enter into nano-scale, dielectrics used in integrated circuits become versatile. Extensive study of these newly introduced materials is necessary to optimize the circuit performance. Oxynitride provide dielectrics with additional latitude to tailor their properties by adjusting the incorporated nitrogen content. Currently oxynitrides have found wide applications in the gate dielectric for CMOS devices, the charge-trapping layer and tunnel/inter-poly dielectric for non-volatile memories and the storage dielectric for DRAM cell capacitors. With the progress of microelectronic industry, new devices will certainly be developed and oxynitride will undoubtedly play a crucial role in exploring the next-generation devices. Gas barrier thin film is another promising area for the applications of oxynitrides. Currently AlO<sub>x</sub> and SiO<sub>x</sub> are the most widely used materials for gas barriers. However, AlO<sub>x</sub>N<sub>y</sub> has been demonstrated to have better gas barrier performance than its counterpart oxide. In addition, recent research results showed that transition metal oxynitrides (TMeO<sub>x</sub>N<sub>y</sub>) displayed comparable gas barrier performance as other conventional oxides, and the adjustable optical and electrical properties are especially attractive. To enhance the gas barrier performance, there are two major approaches: a) increasing the packing density of the barrier film and b) multilayer structures. For applications requiring extremely low gas permeation, such as flexible OLED, multilayer structures comprised of alternating polymer and inorganic layers are much better than the single-layer films. However, finding barriers with satisfying performance at a cost that is compatible with large-scale, low-cost manufacturing still remains a challenging issue.