Hi there,
I am specifically looking for commercial and/or lab-made wet etchants options for etching specifically glass substrate and/or SiO2 with the underneath Si substrate. In my device, I have metal electrodes that are separated by micron gaps on top of the glass or SiO2/Si substrate. I would like to etch the underneath substrate wherever the micron gap exists and leaving the metal electrodes intact.Is there any suggestions, I appreciate your valuable suggestions in advance.
Wet etch of an amorphous layer, like SiO2 o other glass, is by itself ISOTROPIC. any wet etch will always result in a lateral etched part as well, so that the final lateral profile forms a 45 deg angle to the surface plane. In other words, you will cause an etch under the metal pads border for an extension comparable to the depth of your etched region.
To get a vertical (unisotropic) etch you must resort to more complex dry or mixed dry/wet etch processes that requires dedicated machines to carry on (e.g., plasma etchers)
I agree with Giuseppe Curro. Also there is a lot of literature out there about reactive ion etching (Dry Etching) and wet etching. If direction is important and you want to drill down only (anisotropic) then really Dry Etch is the only way to go. A lot of control is lost with wet etch where is it much more isotropic (non-directional). Below is a quickly picked reference that talks about wet and dry etch is as follows. It provides more description to your problem. Lucky for you there's a lot of literature out there to look into various types of chemistry as there are lots of dry and wet etch systems. So there should be some good ideas to follow given whatever you are trying to do!
https://www.ece.ucdavis.edu/~anayakpr/Papers/Wet%20and%20Dry%20Etching_submitted.pdf
Giuseppe Curro and John Reye Thank you both, the reference document you provided is useful, I am also reading many papers and figured it out that I would better go for Dry etching.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Inorganic Materials
- Ceramics
- Glass