2 Supporting Text

2.1 Pixel characteristics as a function of heater temperature

Fig. S3A shows radially averaged cross section of pixels formed at heater temperatures varying between 200 and 500 °C. At a heater temperature of 200 °C the indent (pixel) is surrounded by a pronounced pile-up of material termed rim. This rim formation is characteristic for hot embossing (S8) and results from volume conservation. It has been shown also for hot embossing that regardless of the heater temperature, the height of the rim is typically a 10-20 % fraction of the indent depth (S8). For the molecular glass material, in contrast, the height of the rim decreases significantly at heater temperatures of 300 °C and above, which is a clear sign, that the volume is not conserved. Another clear signature of hot embossing is the interference of neighboring indents, leading to the erasure of the first written indent by the second indent (S9). To study the erase-characteristics, we write indent pairs at varying indent pitch p and plot the cross section through the centers of both indents. Fig. S3B shows the result of such an analysis, the cross-sections are encoded in color and stacked in the y-direction of the image. At a low writing temperature of 200 °C, strong erasure is observed for a pitch less than 30 nm (indicated by the circles), as expected for hot embossing. Conversely, at a heater temperature of 500 ^°C, the indents merge to form an elongated mark and the material between the indents is completely removed.

2.2 Transport model

Given the nanoscale nature of the process, there is no experimental technique available to study the transport of the molecules in-situ. Correspondingly we have to rely on indirect evidence to draw conclusions on the transport path. First we list the experimental observations:

1. The T-F diagram in Fig. 1 of the manuscript shows the thermo-mechanical behavior of the material at the micro-second timescale. From the linear force-temperature correlation for a given indent depth, we can unambiguously assign the low temperature behavior to a mechanical embossing regime. When the pixel formation becomes independent of the applied force (intersection of the linear lines), the material has lost its resistance against deformation at the timescale of the experiment (at a heater temperature of 350 ^°C). As discussed in the manuscript and in the section 'temperature calibration' above, this heater temperature corresponds to an elevated temperature on the resist surface of « 170 °C, the softening temperature of the material.

2. The results shown in Fig. 2 of the manuscript demonstrate, that patterning is possible at a heater temperature of 300 °C, very close to the softening temperature. As discussed in the previous section, we have observed, that at this temperatures of 300 °C the writing mech­anism for a single pixel changes from volume preserving hot embossing to a mechanism in which the volume is consumed.

3. A volume of w 0.5/xm³ of material has been removed from the sample surface (see section 'Tip endurance' below), however no traces of the material could be detected on the tip or on the substrate by SEM and AFM inspection.

4. We know that the physical vapor deposition temperature in vacuum is 220 ^°C, which is significantly higher than the softening temperature of the material of 170 °C. During the PVD process, the molecules do not disintegrate as we have verified by FTIR experiments.

5. We know that the material exhibits excellent wetting behavior on SiOx (see section 'Ma­terial details' above).

From these observations we draw the following conclusions: From 1) and 2) it is clear that during the patterning process material is removed from the sample, starting at a heater temperature of 300 °C (resist temperature of 150 °C). From 3) it follows that a major part of the material has escaped into the environment. From 4) it follows that the temperature supplied by the tip is not sufficient to directly evaporate the material into the atmosphere at a microsecond time scale (at a heater temperature of 300 °C).

To reconcile all the observations and conclusions we propose the following model: At a heater temperature of > 300 °C the tip is able to liquefy the molecules close to the tip-sample contact zone. The molecules diffuse along the tip into hotter regions, until they acquire suffi­cient thermal energy for evaporation. This notion of molecular diffusion along the tip is further corroborated by 5). From 4) we conclude that the molecules do not disintegrate in the evap­oration process. This is further corroborated by 3). Otherwise, reactive fragments would be created during evaporation. We know from our data storage project that these products rapidly contaminate the tip which can be easily detected by SEM inspection.