Semiconductor devices with magnetic regions and stressor structures
View Patent ↗A magnetic cell core includes at least one stressor structure proximate to a magnetic region (e.g., a free region or a fixed region). The magnetic region may be formed of a magnetic material exhibiting magnetostriction. During switching, the stressor structure may be subjected to a programming current passing through the magnetic cell core. In response to the current, the stressor structure may alter in size. Due to the size change, the stressor structure may exert a stress upon the magnetic region and, thereby, alter its magnetic anisotropy. In some embodiments, the MA strength of the magnetic region may be lowered during switching so that a lower programming current may be used to switch the magnetic orientation of the free region. In some embodiments, multiple stressor structures may be included in the magnetic cell core. Methods of fabrication and operation and related device structures and systems are also disclosed.
1. A semiconductor device, comprising:
a magnetic region; and
a stressor structure adjacent the magnetic region and configured to vertically expand or vertically contract relative to the magnetic region, the stressor structure configured to exert a vertical stress upon the magnetic region and alter a magnetic anisotropy of the magnetic region when the stressor structure is subjected to a programming current.
2. The semiconductor device of claim 1 , wherein a coefficient of thermal expansion of the stressor structure is different than a coefficient of thermal expansion of the magnetic region.
3. The semiconductor device of claim 1 , wherein the stressor structure comprises aluminum, copper, silicon, or germanium.
4. The semiconductor device of claim 1 , wherein the stressor structure comprises a piezoelectric material.
5. The semiconductor device of claim 1 , wherein the magnetic region comprises CoFeB.
6. The semiconductor device of claim 1 , wherein the magnetic region exhibits a switchable magnetic orientation.
7. The semiconductor device of claim 1 , wherein the magnetic region is configured to exhibit a reduced perpendicular magnetic anisotropy responsive to the vertical stress exerted by the stressor structure.
8. The semiconductor device of claim 1 , wherein:
the stressor structure is configured to vertically contract; and
the magnetic region exhibits a negative magnetostriction.
9. The semiconductor device of claim 1 , further comprising another stressor structure proximate another magnetic region.
10. The semiconductor device of claim 9 , wherein:
the another magnetic region is configured to exhibit a positive magnetostriction and the another stressor structure is configured to vertically contract; and
the magnetic region is configured to exhibit a positive magnetostriction and the stressor structure is configured to vertically expand.
11. The semiconductor device of claim 9 , wherein:
the another magnetic region is configured to exhibit a positive magnetostriction and the another stressor structure is configured to vertically expand; and
the magnetic region is configured to exhibit a negative magnetostriction and the stressor structure is configured to vertically expand.
12. The semiconductor device of claim 11 , wherein the stressor structure and the another stressor structure comprise the same material.
13. A semiconductor device, comprising:
a magnetic region having one of a fixed magnetic orientation and a free magnetic orientation and configured to exhibit a positive magnetostriction; and
a stressor structure adjacent the magnetic region, the stressor structure configured to vertically contract or vertically expand to exert a vertical stress on the magnetic region.
14. The semiconductor device of claim 13 , wherein the stressor structure comprises a discontinuous stressor structure.
15. The semiconductor device of claim 13 , wherein the stressor structure comprises multiple discrete stressor features separated from one another.
16. The semiconductor device of claim 13 , wherein the stressor structure is directly adjacent to the magnetic region.
17. The semiconductor device of claim 13 , further comprising an intermediate structure between the magnetic region and the stressor structure.
18. A semiconductor device, comprising:
a magnetic region; and
a stressor structure directly contacting the magnetic region, the stressor structure configured to vertically expand or vertically contract and exert a stress upon the magnetic region when the stressor structure is subjected to an electrical current passing,
the magnetic region configured to alter in size responsive to the stress exerted by the stressor structure to alter a magnetic anisotropy exhibited by the magnetic region.
19. The semiconductor device of claim 18 , wherein:
the magnetic region comprises a free region; and
the magnetic region is configured to alter in size responsive to the stress exerted by the stressor structure to decrease the magnetic anisotropy thereof.
20. The semiconductor device of claim 18 , further comprising another magnetic region and another stressor structure in contact with the another magnetic region, wherein the another stressor structure is located on a side of the another magnetic region opposite the magnetic region.