Depth profile studies of ZrTiN coatings by laser ablation inductively coupled plasma mass spectrometry
| Authors | |
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| Year of publication | 2004 |
| Type | Article in Periodical |
| Magazine / Source | Analytical and Bioanalytical Chemistry |
| MU Faculty or unit | |
| Citation | |
| Field | Analytic chemistry |
| Keywords | Laser ablation - Inductively coupled plasma mass spectrometry - Excimer laser - Beam homogenizer - ZrTiN - Coating - Depth profiling - Depth resolution - Aspect ratio |
| Description | Abstract Feasibility of depth profiling was studied using a 193 nm ArF* excimer laser ablation system (GeoLas, MicroLas, Goettingen, Germany) with the lens-array-based beam homogenizer in combination with ICP-QMS Agilent 7500. Two ablation cells (20 cm3 and 1.5 cm3) were compared at the laser repetition rate of 1Hz, laser beam energy of 135 mJ and the carrier gas flow rate 1.5 L/min He + 0.78 L/min Ar. Dimensions of ablation cell are important parameters for signal tailing, however; very small cell volumes (e.g. 1.5 cm3) may cause memory effects, which can be probably explained by dominant inertial losses of aerosol on cell walls with its delayed mobilization. The 20-cm3-ablation cell seems to be appropriate for depth profiling by continuous single-hole drilling. The study of influence of the pit diameter magnitude on courses of waning and emerging signals under small crater depth/diameter aspect ratio, which ranges between 0.75 and 0.0375 for the 3-ěm thick coatings and pit diameters 4-80 ěm, revealed that the steady-state signals of pure coating and pure substrate (out of interface) were obtained at crater diameters between 20-40 ěm. Depth resolution defined by means of slopes of tangents in the layer interface region depends on the pit diameter with optimum in the range of 20-40 ěm and makes 0.6 ěm for 20-ěm pit. In-depth variation of concentration of coating constituent (Ti) was proved almost identically using two different laser/ICP systems. |
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