Recently, radio frequency (RF) reflectometry techniques have been employed in dispersive gate-based sensing across multiple quantum dot platforms to perform sensitive charge-based state read-out. Here, we extend such techniques to a mK-STM by integrating an LC tank circuit directly into the tip plate to enable simultaneous measurement of tunneling current and RF-reflectometry. For semiconductor samples of interest, STM tip-induced band bending gives rise to the formation a quantum dot which can then be scanned across a sample surface to sense defects via changes in tip-sample capacitance. This measurement geometry provides a unique method of probing new materials as only a single lead is needed to both create and measure the properties of the tip induced dot. This reduced overhead presents a new non-destructive method of characterization of materials that can be employed in QIS applications. As a demonstration of this capability, we present spectroscopic measurements on a series of Si(100) samples doped with varying concentrations of phosphorus (N_D ~10¹⁷ to 10¹⁹ cm^-3). Our results reveal phase contrast in the vicinity of both surface defects and sub-surface dopants. At lower dopant concentrations, RF phase-resolved spectral features appear to broaden while the apparent STM tip-sample bias voltage hysteresis drastically increases. This hysteresis, which manifests as changes to spectral features pending the sweep direction (i.e. negative bias to positive, and vice versa), suggests conditional charging effects based on the initial state of the induced dot. Here, we specifically focus on extensive ‘line-style’ phase spectroscopy measurements on a Si(100) sample possessing a concentration of N_D = 4.3∙10¹⁸ cm^-3 with a specific focus on the hysteresis dependent features. These measurements yield fine parabolic-like patterns indicative of surface defects, while larger underlying charge structures that emerge in the background can be attributed to sub-surface dopants. From these results, we aim to understand how the local environment of novel materials lead to deformations in the confining potentials of dot-based qubits.