Edward W. Budiarto

Carrier illumination for characterization of ultrashallow doping profiles

The Carrier Illumination™ (CI) method is an optical technique for nondestructive in-line monitoring of postanneal junction depth, preanneal preamorphization implant depth, and dose. This work intends to extend the use of the CI measurements from a relatively process specific quantitative measurement towards a more universal quantitative analysis of junction depth, profile abruptness, and implant dose. For that purpose the predictive capabilities of the present physical models with respect to the quantitative dependence of the CI signal on the applied generation power is investigated for a wide variety of samples, including bulk material, highly abrupt chemical vapor deposition grown (B) structures, and implanted ultrashallow junctions (B, BF2, As). In general, the CI signal may arise from a combination of three components: a primary one originating from the reflection of the probe laser beam from the dopant profile depth corresponding with the injected excess carrier level, in some cases, from reflection ...

Junction and Profile Analysis using Carrier Illumination

Carrier Illumination™ (CI) is an optical technique for non-destructive in-line monitoring of post-anneal junction depth and pre-anneal PAI depth and dose with wafer mapping capabilities. This work intends to extend the use of the CI-measurements from a range-specific quantitative measurement towards a more universal quantitative analysis of junction depth, profile abruptness and implant dose. For that purpose this paper presents a systematic study of the CI response to a wide variety of post anneal implant processes, varying parameters including implant species, dose and energy, annealing condition, and surface preparation. Samples containing B, BF 2 and As-implants with and without Ge PAI layers, with junction depths between 10-120 nm, were measured. In addition near-ideal box-like profiles (as obtained with CVD-growth) were fabricated and measured. For the abrupt CVD profiles, CI measures the junction position with sub-nm resolution independent of the CI-analysis conditions. For more graded profiles resulting from annealed implants, the correlation to the SIMS junction depth becomes a function of generation laser current (which is proportional to the applied power). As the concentration level, at which the correlation is made, can be adjusted over a concentration range of approximately 2x10 18 to 2x10 19 /cm 3 by changing the laser current, a route towards correlating the CI measurement with profile abruptness becomes feasible.