Bulk changes in semiconductors using scanning probe microscopy:  nm-size fabricated structures

Abstract

Hemispherical p/n/p transistor structures ranging from 100 m down to 0.05 m in diameter are fabricated in CuInSe 2 , by application of a high electric field between a conducting diamond tip of an atomic force microscope and a CuInSe 2 crystal. This leads to electromigration of Cu ions in the bulk of the material. The results of this thermally assisted process are the transistor structures. These are characterized by scanning spreading resistance microscopy. For large devices these results are compared and found to agree with those of ''conventional'' electron-beam-induced current ones. Removing several tens of atomic layers from the top surface of a structure does not affect the spreading resistance image of the device. This indicates the threedimensional hemispherical nature of the structures.

Scanning tunneling microscope-induced modification of Ag films and nanowire arrays on Cu(100) surfaces

“…Atomic resolution images of the c(10ϫ2) and (111)-(1 ϫ1) structures are shown in Figs. 16 Figure 2͑d͒ shows an atomic resolution image of the pit created in Fig. These findings are consistent with previous STM studies of this system.…”

Current Imaging and Electromigration-Induced Splitting of GaN Nanowires As Revealed by Conductive Atomic Force Microscopy

“…It is interesting to find out the factors that dominate wire splitting. It was reported that the tip-to-substrate Joule heating current above 1 μA in C-AFM may result in a temperature increase of 100−500 °C based on the heat flow equation, , Δ T = 0.5 P o /π KR where P o is the average power dissipated around the contact, K is the thermal conductivity, and R is the spherical contact radius. Assuming that all of the power P dissipated around the contact, and using the values of R from a few nanometers (for surface protrusions) to 20 nm (for smooth surface; typical tip radius), and K = 130 W/(m·K) for GaN in our case, we obtained Δ T ≪ 1 °C in our case.…”

Investigation of capacitance transients in CuInS2 due to ionic migration

“…Under specific circumstances Cu-transport can be used to change the semiconductor type. In this way p-n homojunctions or nano-scaled transistors are created in chalcopyrites [14][15][16][17][18][19][20]. Furthermore, it has been shown that Cu(In,Ga)Se 2 -based solar cells also recover after a decrease in efficiency caused by electron or proton irradiation [21][22][23].…”