Low-k SiC_xN_yFilms Prepared by Plasma-Enhanced Chemical Vapor Deposition Using 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane Precursor

Abstract

Low-k silicon carbonitride (SiC x N y ) films with k of 3.6-4.6 were prepared by radio frequency plasma-enhanced chemical vapor deposition at 25 to 400 • C under low power density of 0.15 W/cm 3 , using a single source precursor, 1, 3, 5-trimethyl-1, 3, 5trivinylcyclotrisilazane (VSZ), and Ar. At lower deposition temperatures (≤ 200 • C), most cyclic VSZ structures were preserved in the SiC x N y films, resulting in a lower density (1.60-1.76 g/cm 3 ), a lower dielectric constant (k∼3.6-3.9) and a fairly good elastic modulus of 22.0-25.0 GPa. When the deposition temperature was raised to 400 • C, the cyclic N-Si-N linkages were reformed to a dense Si-N structure, with the desorption of CH x bonds, resulting in higher density (2.0 g/cm 3 ), a dielectric constant of 4.6, and an excellent elastic modulus of 65.2 GPa. The leakage current density of SiC x N y films was reduced from 1.5×10 −6 to 4.0×10 −8 A/cm 2 at 1 MV/cm, upon increasing the deposition temperature from 25 • C to 400 • C. The conduction mechanism of the SiC x N y films, except the film deposited at 400 • C and tested under higher electric field, exhibited Schottky emission due to few charged defects by using a cyclic VSZ precursor and a lower plasma power density of 0.15 W/cm 3 .

Pore morphology of low-k SiCxNy films prepared with a cyclic silazane precursor using plasma-enhanced chemical vapor deposition

“…The formation of big cages was attributed to the linear chains and short fragments from the breakup of the cyclic rings [13]. To elucidate the formation mechanism of the relatively large pores in our study, we refer to FTIR analysis of such SiC x N y films asdeposited at 100°C and 300°C in our previous work [14]. At low deposition temperatures (≤200°C), most of the cyclic structures of VSZ were preserved in the SiC x N y films after the PECVD process.…”

“…At low deposition temperatures (≤200°C), most of the cyclic structures of VSZ were preserved in the SiC x N y films after the PECVD process. Still, some of the cyclic N\ \Si\ \N bonds were opened and broken into the small fragments such as -Si-N- [14]. Moreover, during the plasma deposition process, the vinyl side-groups in VSZ could be readily activated and reacted to form the long organic chain, such as Si-(CH 2 ) n -Si and/or Si-(CH 2 ) n -CH 3 [14,26,27].…”

“…In specific, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane (VSZ) with 3 vinyl side-groups was used as a single precursor using radio-frequency (RF) PECVD technique at a low power density (0.15 W/cm 3 ). The deposition temperatures ranging from 25 to 400°C yield low-k SiC x N y films with k from 3.6 to 4.6 [14]. Their film densities were 1.6-2.0 g/cm 3 , which are considerably lower than the density of Si 3 N 4 films (k = 7.5; ρ = 3.1 g/cm 3 ) [15] or SiC x N y (BASICN TM 400) films (k = 4.3; ρ = 1.86 g/cm 3 ) [11].…”

Study of Cu diffusion behavior in carbon rich SiCN:H films deposited from trimethylphenylsilane

“…Its main disadvantage is high dielectric constant. Therefore, amorphous silicon carbide (SiC x :H) [6,7] and carbonitride (SiC x N y :H) [8,9] films have recently attract much attention for Cu capping / diffusion barrier application. Integration of such materials into microelectronic circuits, however, poses a number of challenges, as the materials must meet strict requirements in terms of properties and reliability.…”

Effect of Porogen Incorporation on Pore Morphology of Low-k SiCxNyFilms Prepared Using PECVD

“…• C. 11 These asdeposited films also possess low film density of 1.6-2.0 g/cm 3 , which can be attributed to the existence of micropores, but limited porosity, in the as-deposited SiC x N y films due to the induced pores resulting from organic phase and the formation of Si-(CH 2 ) n -Si with the matrix structure. 12 In order to explore and fabricate porous SiC x N y films with higher porosity, a sacrificial porogen, epoxycyclohexane (ECH) as illustrated in Fig.…”