Errors and Error‐Avoidance in the Schottky Coupled Surface Photovoltage Technique

Abstract

We have examined sources of error and techniques for error avoidance in Schottky barrier surface photovoltage measurements. In particular we have used a computer simulation approach to gauge the errors in the method A formalism, which is applied to analyzing constant open-circuit voltage measurements, and in the method B formalism, which is applied to analyzing constant light flux measurements. As a result of this analysis, we have shown we can eliminate the extreme measurement precautions necessitated by method B through the use of a new method C formalism which is introduced here. We also show that, for measured diffusion lengths less than one-third the sample thickness, the measurement is shown to be forgiving of the state of the back contact if that surface has flat or accumulated bands; however, if the back surface is rectifying, the range of the measurement validity can be affected by the magnitude of the front contact barrier height, even with the measured diffusion length less than one-third the sample thickness.

Surface photovoltage phenomena: theory, experiment, and applications

“…A key to the large difference between theory and experiment in this case may be found in the work of Howland and Fonash [532]. These authors have compared between the two SPV methods for the case of a Schottky contact.…”

“…The latter is merely an approximation, which assumes that all SCR generation/recombination processes may be effectively lumped in a single SRV-like parameter. This assumption has been examined by increasingly elaborate numerical simulations as well as analytical developments [77,78,80,89,441,532,535,536]. It was usually found to be satisfactory (i.e., introducing an error of several percent at most) for free surfaces as well as Schottky contacts, including cases with minority carrier trapping.…”

Physical understanding and technological control of carrier lifetimes in semiconductor materials and devices: A critique of conceptual development, state of the art and applications

“…11b) [68][69][70][71][72][73][74][75][76]. Its attractive features include its nondestructive and contactless measurement approach.…”

Etch‐Induced Physical Damage and Contamination during Highly Selective Oxide Etching Using C 4 F 8 / H 2 Helicon Wave Plasmas

“…The physical and electrical damage received on the exposed silicon wafer during the 50% overetching of 1 m phosphosilicate glass with C 4 F 8 and 70% C 4 F 8 /30% H 2 , and the recovery of the physical and electrical defects after the postetch treatment processes, were investigated using HRTEM for physical defects and using a SPV technique for electrical defects. 18 On both the silicon surfaces overetched with C 4 F 8 and 70% C 4 F 8 /30% H 2 , physical defects were observed, and the depth of the defects in wafers overetched with 70% C 4 F 8 /30% H 2 was greater (550 Å) than those with C 4 F 8 (250 Å), possibly due to energetic hydrogen ion implantation and diffusion. Figure 5 shows HRTEM of the defects observed on the silicon surface overetched with C 4 F 8 (a) and with 70% C 4 F 8 /30% H 2 (b).…”