Boron rich boron carbides such as the rhombohedral B13C2 exhibit high hardness , high thermal stability, and high chemical resistance. Since 10 B has a high absorption cross section for thermal neutrons, thin films of B isotope enriched boron rich boron carbides (BxC) have been investigated as neutron converter layer for neutron detectors. Given the He shortage , B detectors are a viable replacement to He detectors in large scale neutron facilities. A suggested evolution of a solid-state neutron detector will require filling of high-aspect ratio vertical holes with neutron converter material. The premier film deposition technique for conformal films is atomic layer deposition (ALD) which is based on self-limiting surface reactions of gas phase precursors separated by inert gas, which enables conformal coverage of high surface area features. However, only a few ALD processes have been reported for carbide materials, mainly due to the lack of a suitable carbon precursor; the few examples are TaCx , TiCx , WCx and FeCx . Since BxC films can easily be deposited by thermal chemical vapor deposition (CVD) with a continuous gas flow, it is of great interest to develop conformal CVD processes for BxC films. Continuous CVD processes can be tuned to yield conformal deposition and even super-conformal deposition in some conditions. Abelson and Girolami describes how a high degree of conformal coverage in continuous CVD can be achieved by reducing the surface reaction probability, β, defined as the ratio of the number of precursor molecules that stick to the surface to the total number of incoming molecules. A lower value of β means that the molecules arriving at the surface are more probable to be re-emitted to the gas phase rather than being chemisorbed. Alternatively, using precursors exhibiting site blocking on the growth surface or addition of a molecular surface inhibitor can enhance surface site blocking to enable a conformal CVD. Triethylboron, B(C2H5)3 (TEB), and trimethylboron, B(CH3)3 (TMB), are popular boron CVD precursors that can be used as single source precursors to deposit BxC films.