VCSEL Quick Fabrication for Assessment of Large Diameter Wafers - data

Stripped-back representative VCSEL devices with a simple fabrication process that very closely approaches the performance of standard BCB-planarised devices have been produced. These VCSEL Quick Fabrication (VQF) devices achieve threshold currents only 0.3 mA higher than that of a standard device produced from the same material. The predictability of standard performance from VQF performance is also robustly assessed in terms of temperature effects to account for the observed disparities.

This dataset contains 10 sub-folders named "Figure X" with X corresponding to the figure number.

In "Figure 3" are two sub-folders containing raw P-I-V data for both VQF and standard devices. Within the folders "VQF" & "Standard" are 7 sub-folders "XX" identifying different regions of the sample. Within these folders are sub-folders "MEAS_XX" which refer to measurement conditions for the arbitrary device number.  The files at the end of the folder structure, labelled "DXX_PIV.....", contains the raw PIV data. From the columns labelled "Current" and "Voltage", the series resistance was extracted as the slope between 2.4 and 2.5 V.

In "Figure 4" are two sub-folders containing raw P-I-V data for both VQF and standard devices. Within "VQF" & "Standard" are 7 sub-folders "XX" identifying different regions of the sample. Within these folders are sub-folders "MEAS_XX" which refer to measurement conditions for the arbitrary device number.  The files at the end of the folder structure, labelled "DXX_PIV.....", contains the raw PIV data. From the columns labelled "Current" and "Power", the threshold current was extracted as the current corresponding to the maximum of the second derivative of P(I).

In "Figure 5" are two sub-folders corresponding to the top and bottom plots of Figure 5. In "Top" are three sub-folders containing raw P-I-V data for a range of temperatures, corresponding to 7 & 9 um aperture VQF devices and an 8um standard device. These sub-folder names details the oxide aperture diameter of the DUTs. Within "Top" and "Bottom" are folders labelled "XX degC" which details the temperature at which the measurements are taken. At the end of the folder structure are the files labelled "DXX_PIV", where DXX is the arbirary device number. From these files the threshold current was extracted and plotted against the temperature. In "Bottom" are three sub-folders containing P-I-V data up to thermal rollover, corresponding to 7 & 9 um aperture VQF devices and an 8um standard device.

In "Figure 6" are three sub-folders corresponding to 1 & 3um aperture VQF devices and a 2um aperture standard device, with the sub-folder names detailing the oxide aperture diameter of the DUTs. Within each of these folders are lasing spectra data, where colums "lambda_in_nm" and "R:spectrum(1,1), refer to the wavelength range and measured intensity, respectively. From this the spectra are plotted and the wavelength of the fundamental mode is extracted. 

In "Figure 7" is a folder structure equivalent to "Figure 6", however, these folder contain spectral data for 7 & 9um VQF devices and 8um standard device.

In "Figure 8" are two sub-folders corresponding to standard and VQF devices. Within these folders are 16 sub-folders referring to different regions of the sample. Continuing through the folder structure gets to a folder named "WPro_VCSEL_EOv1~WX_EO_VCSEL_EO_MXX", with XX referring to the mesa diameter of the DUT. Within these folders are data files labelled "DXX.....Spectrum" which contains lasing spectra data from which the fundamental mode wavelength was extracted and plotted against oxide aperture in the same way as for "Figure 6 & 7".

In "Figure 9" are two sub-folders corresponding to the top and bottom plots of figure 9. In "Top" is a raw data (.DAT) file from which the wafer map is plotted. Colums 1 & 2 are the X and Y coordinates in mm. Colum 8 is the material cavity resonance wavelength. In "Bottom" are sub-folders whose name refers to location on a 6-inch wafer by XY tile label (horizontal line profile at Y = -9mm). X1 refers to the West of the wafer and X12 the East. Within these folders are sub-folders referring to locations within 12.5x12.5mm tiles, with the same structure as for that in "Figure 3 & 4". Under the location identifier "BC" and measurement condition folder "MEAS_56" at the end of the folder structure, are data files containing lasing wavelength data for devices along the line profile. The line profile for the cavity resonance wavelength is extracted from the data file in "top".

In "Figure 10" are two sub-folders. In "oxidation" is an excel file containing data from infrared camera measurements of oxidation length taken at various locations on the wafer (horizontal & vertical directions). The coordinates (in mm) of where the measurements were performed is the "x" column of the data. In "Resistance" are sub-folders detailing location on wafer (in the same way as in "Figure 9"), which contains sub-folders referring to different locations within the 12.5x12.5mm tiles. Continuing to the end of folder structure through "MEAS_56" leads to P-I-V datafiles, labelled "D56_PIV...". From the columns labelled "Current" and "Voltage", the series resistance was extracted as the slope between 2.4 and 2.5 V. The resistance was plotted against the wafer X coordinate of the device, converted to mm.

In "Figure 11" are two sub-folders corresponding to the top and bottom images of figure 11. In "Top" are 96 sub-folders referring to 96 tiles on a 6-inch wafer. In the same way as for "Figure 10" continuing through "MEAS_56" results in P-I-V data files labelled "D56_PIV..." from which the threshold current was extracted and plotted against XY coordinates to create a heatmap. The XY coordinates are are labelled in the subfolder names. In "Bottom" is a data file of the threshold current density extracted from the data of "Top" for the X=6 subfolders.

In "Figure 12" are subfolders corresponding to temperature of measurement. Within the subfolders are two XY folders, with X6_Y6 referring to devices from the centre of the wafer and X11_Y6 referring to edge. Continuing through the folder structure though "D57" for X6_Y6 and "D59" for X11_Y6 leads to raw P-I-V data files labelled "...D57_PIV...." or "...D59_PIV..." whereby equal oxide apertures are compared (D57 for centre and D59 for edge produces12.5 um oxide aperture). From these data files the threshold current is extracted and threshold current density calculated for each temperature.  

Research results based upon these data are published at http://doi.org/10.1109/JPHOT.2022.3169032