Carbon-related defects in Si:C/silicon heterostructures assessed by deep-level transient spectroscopy

This paper reports on a Deep-Level Transient Spectroscopy (DLTS) study of the electrically active defects in similar to 100 nm Si: C stressors, formed by chemical vapor deposition on p-type Czochralski silicon substrates. In addition, the impact of a post-deposition Rapid Thermal Annealing (RTA) at 850 degrees C on the DLT-spectra is investigated. It is shown that close to the surface at least two types of hole traps are present: one kind exhibiting slow hole capture, which may have a partial extended defect nature and a second type of hole trap behaving like a point defect. RTA increases the concentration of both hole traps and, in addition, introduces a point defect at EV + 0.35 eV in the depletion region of the silicon substrate at some distance from the Si: C epi layer. This level most likely corresponds with CiOi-related centers. Finally, a negative feature is found systematically for larger reverse bias pulses, which could point to a response of trap states at the Si: C/silicon hetero-interface

N-(2-Formyl­phen­yl)benzene­sulfonamide

In the title compound, C13H11NO3S, the two aromatic rings are oriented at an angle of 88.18 (8)°. Intra­molecular N—H⋯O and C—H⋯O hydrogen bonds are observed, each of which generates an S(6) ring motif. In the crystal, mol­ecules are linked into C(7) chains along [010] by inter­molecular C—H⋯O hydrogen bonds. The structure is further stabilized by inter­molecular C—H⋯π inter­actions involving the sulfonyl-bound phenyl ring

Diethyl 2-(2-nitro­benzyl­idene)malonate

In the title compound, C14H15NO6, the ethoxy­carbonyl groups adopt extended conformations. In the crystal, mol­ecules are linked into centrosymmetric dimers via pairs of C—H⋯O hydrogen bonds with a R 2 2(20) motif

2-Chloro­methyl-3-methyl-1-phenyl­sulfonyl-1H-indole

In the title compound, C16H14ClNO2S, the phenyl ring makes a dihedral angle of 78.1 (1)° with the indole ring system. The mol­ecular structure is stabilized by weak intra­molecular C—H⋯O inter­actions. The crystal structure exhibits weak inter­molecular C—H⋯O, C—H⋯π and π–π [centroid–centroid distances = 3.620 (1)–3.794 (1) Å] inter­actions

N-[(3-Phenyl­sulfanyl-1-phenyl­sulfonyl-1H-indol-2-yl)meth­yl]propionamide

In the title compound, C24H22N2O3S2, the phenyl rings form dihedral angles of 75.2 (1) and 86.1 (1)° with the indole ring system. The mol­ecular structure is stabilized by intra­molecular C–H⋯O and N—H⋯O hydrogen bonds. The crystal structure exhibit inter­molecular N—H⋯O and C—H⋯O hydrogen bonds, C—H⋯π and π–π [centroid–centroid distance = 3.748 (1) Å] inter­actions

(2-Methyl-1-phenyl­sulfonyl-1H-indol-3-yl)phenyl­methyl acetate

In the title compound, C24H21NO4S, the indole ring system makes dihedral angles of 77.8 (1) and 85.4 (1)°, respectively, with the S- and C-bound phenyl rings. The mol­ecular structure is stabilized by a weak intra­molecular C—H⋯O hydrogen bond. In the crystal, a weak inter­molecular C—H⋯O hydrogen bond and a C—H⋯π inter­action are also observed

(4-Bromo­phen­yl)(1-phenyl­sulfonyl-1H-indol-2-yl)methanone

In the title compound, C21H14BrNO3S, the indole ring system forms dihedral angles of 65.64 (8) and 59.30 (8)°, respectively, with the phenyl and bromo­phenyl rings. In the crystal, mol­ecules are connected by a C—H⋯O hydrogen bond, forming a chain along [101]. The chains are further connected by weak inter­molecular C—H⋯π inter­actions, forming a layer parallel to the ac plane

1,3-Dimethyl-5-(2-methyl­benzyl­idene)pyrimidine-2,4,6(1H,3H,5H)-trione

In the title compound, C14H14N2O3, the dihedral angle between the pyrimidine and benzene rings is 14.9 (1)°. The mol­ecular structure is stabilized by weak intra­molecular C—H⋯O inter­actions and the crystal structure exhibits a weak inter­molecular π–π inter­action [centroid–centroid distance = 3.575 (3) Å]

5-Methyl­phenanthro[2,3-b]thio­phene

The title compound, C17H12S, which crystallises with two molecules in the asymmetric unit, features four fused rings forming an essentially planar mol­ecule, with maximum deviations from the mean plane of 0.078 (2) and 0.080 (2) Å for C atoms of the thio­phene and phenanthrene groups in both the mol­ecules. The crystal packing features weak C—H⋯π inter­actions

tert-Butyl 3-[2,2-bis­(ethoxy­carbon­yl)vin­yl]-2-bromo­methyl-1H-indole-1-carboxyl­ate

In the title compound, C22H26BrNO6, the indole ring system is planar [maximum deviation 0.029 (2) Å]. The tert-butyl bound carboxyl­ate group forms a dihedral angle of 17.54 (8)° with the indole ring system. In the crystal, mol­ecules are linked into centrosymmetric R 2 2(10) dimers by paired C—H⋯O hydrogen bonds