Metal etch process selective to metallic insulating materials
View Patent ↗A method is provided which includes patterning one or more metal layers arranged above a metal insulating layer and terminating the patterning process upon exposure of the metal insulating layer. In particular, the method may be adapted to be more selective to the metal insulating layer than the one or more metal layers. In general, such an adaptation may include exposing the semiconductor topography to an etch chemistry comprising hydrogen bromide. In some cases, the etch chemistry may further include a fluorinated hydrocarbon. In yet other embodiments, the method may further or alternatively include using a reactive ion etch process, etching at a relatively low temperature, using a resist mask, and/or using an etch chemistry substantially absent of an oxygen plasma. In this manner, the method may, in some embodiments, include patterning the one or more metal layers using a reactive ion etch process substantially absent of an oxygen plasma.
1. A method for processing a semiconductor topography, comprising:
depositing a tunneling layer above one or more underlying magnetic layers;
depositing one or more overlying magnetic layers above the tunneling layer;
patterning the one or more overlying magnetic layers with an etch chemistry comprising HBr to form an upper portion of a magnetic cell junction; and
terminating the step of patterning upon exposing the tunneling layer.
2. The method of claim 1 , further comprising patterning a resist mask above the one or more overlying magnetic layers prior to the step of patterning the one or more overlying magnetic layers.
3. The method of claim 1 , further comprising:
depositing an interlevel dielectric above the tunneling layer; and
etching a via within the interlevel dielectric to expose a portion of the tunneling layer.
4. The method of claim 1 , wherein the one or more overlying magnetic layers comprises nickel-iron.
5. The method of claim 1 , wherein the tunneling layer comprises aluminium oxide.
6. The method of claim 1 , wherein the step of patterning is conducted at a temperature between approximately 20° C. and approximately 120° C.
7. The method of claim 1 , further comprising:
depositing a cap layer above the one or more overlying magnetic layers; and
depositing a resist mask above the cap layer prior to the step of patterning the one or more overlying magnetic layers.
8. The method of claim 1 , wherein the etch chemistry further comprises a fluorinated hydrocarbon.
9. The method of claim 8 , wherein the fluorinated hydrocarbon comprises CF 4 .
10. The method of claim 9 , wherein the etch chemistry comprises a HBr:CF4 ratio between approximately 2:1 and approximately 4:1.
11. The method of claim 1 , wherein the step of patterning comprises a reactive ion etch process.