Preferences - General - Appearance - Colors and Fonts
You can select all kinds of different fonts for different areas, but for Javadoc pop-ups there is one font area that is not appearing in the Eclipse font settings list, so I believe this is an oversight by the developers who are responsible for the font selection:
In the Eclipse font settings there is no entry and no term for this, so I am calling it "Javadoc Code Font" and have highlighted it in red circles in the attached picture.
Preferences - General - Appearance - Colors and Fonts
You can select all kinds of different fonts for different areas, but for Javadoc pop-ups there is one font area that is not appearing in the Eclipse font settings list, so I believe this is an oversight by the developers who are responsible for the font selection:
In the Eclipse font settings there is no entry and no term for this, so I am calling it "Javadoc Code Font" and have highlighted it in red circles in the attached picture.