1. A semiconductor device in which current flows between first and second main surfaces of an intrinsic or a first conductivity type semiconductor substrate, comprising:
a first impurity region of a second conductivity type formed on said first main surface side of said semiconductor substrate; and
a second impurity region of the second conductivity type formed on said second main surface of said semiconductor substrate, sandwiching, with said first impurity region, a low concentration region of said semiconductor substrate; wherein
said semiconductor substrate includes a trench reaching said low concentration region of said semiconductor substrate from said first main surface through said first impurity region;
said device further comprising:
a third impurity region of the first conductivity type on said first impurity region to be in contact with a sidewall of said trench at said first main surface of said semiconductor substrate;
a fourth impurity region of the second conductivity type having a higher concentration than said first impurity region, formed on said first impurity region and adjacent to said third impurity region at said first main surface of said semiconductor substrate;
a control electrode layer formed in said trench to oppose to said first and third impurity regions and said low concentration region of said semiconductor substrate with an insulating film interposed, for controlling current flowing between said first and second main surfaces by an applied control voltage;
a first electrode layer formed on said first main surface of said semiconductor substrate and electrically connected to said third and fourth impurity regions; and
a second electrode layer formed on said second main surface of said semiconductor substrate and electrically connected to said second impurity region; wherein
the following expression is satisfied where Dt represents depth of said trench from said first main surface, Wt represents width of said trench, De represents depth of said third impurity region from said first main surface, We represents width of said third impurity region from one of said trenches to another of said trenches, and Pt represents pitch of adjacent said trenches:
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0.4
.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A three-dimensional printing method of manufacturing a pharmaceutical delivery device comprising: a three-dimensionally printed core region comprising at least one pharmaceutical active printed onto and bound to a solid bulk material; a three-dimensionally printed shell region encapsulating the core region and comprising bound solid bulk material; and a transitional region consisting essentially of unbound or partially bound solid bulk material not printed upon, wherein the transitional region is trapped between the core region and the shell region; and the solid bulk material has the same composition in each region; the method comprising:
a) providing a layer of the solid bulk material;
b) dispensing a first fluid onto the layer of solid bulk material to form a first end of the shell region, and optionally repeating a) and b);
c) providing another layer of solid bulk material;
d) dispensing the first fluid onto selected portions of the layer in c) to form portions of the wall of the shell region and a first end of the transitional region, wherein the transitional region consists essentially of trapped unbound or trapped partially bound powder not printed upon; and optionally repeating c) and d);
e) providing another layer of solid bulk material;
f) dispensing a second fluid containing a pharmaceutical active onto predetermined locations of the layer in e) thereby forming one or more portions of the core region surrounded by portions of the transitional region, and dispensing the first fluid onto predetermined locations of the powder layer in e) thereby forming portions of the wall of the shell region; and optionally repeating e) and f), wherein the transitional region consists essentially of trapped unbound or trapped partially bound powder not printed upon;
g) providing another layer of solid bulk material;
h) dispensing the first fluid onto selected portions of the layer in g) to form portions of the wall of the shell region and a second end of the transitional region; and optionally repeating g) and h), wherein the transitional region consists essentially of trapped unbound or trapped partially bound powder not printed upon;
i) providing a layer of the solid bulk material;
j) dispensing the first fluid onto the layer of solid bulk material to form a second end of the shell region, and optionally repeating i) and j); thereby forming the three-dimensionally printed dosage form.
2. A method of manufacturing a three-dimensionally printed dosage form comprising a toxic or potent core region encapsulated within a trapped transitional region and a shell region surrounding the transitional region, wherein the transitional region consists essentially of trapped unbound or trapped partially bound powder not printed upon, the method comprising:
dispensing a first binder fluid which contains neither a toxic or potent excipient onto one or more layers of bulk material to form an end of a shell region;
providing one or more subsequent layers of bulk material and dispensing the first binder fluid thereon to form an end of a transitional region and a perimeter of shell region, wherein the transitional region consists essentially of trapped unbound or trapped partially bound powder not printed upon;
providing one or more subsequent layers of bulk material and dispensing thereon: a) on one or more predetermined locations, a second binder fluid containing a toxic or potent pharmaceutical active to form a core region; and b) the first binder fluid to form a perimeter of shell region and a transitional region between the core region and shell region, wherein the transitional region consists essentially of trapped unbound or trapped partially bound powder not printed upon;
providing one or more subsequent layers of bulk material and dispensing the first binder fluid thereon to form another end of transitional region and a perimeter of shell region, wherein the transitional region consists essentially of trapped unbound or trapped partially bound powder not printed upon; and
providing one or more subsequent layers of bulk material and dispensing thereon the first binder fluid thereby forming another end of shell region.
3. The method of claim 1 or 2, wherein the first or the second liquid further include a binding agent.
4. The method of claim 1 or 2, wherein the pharmaceutical active is a anti-cancer drug, a steroid, a hormone, a narcotic, or another compound having high toxicity or potency.
5. The method of claim 4, wherein the pharmaceutical active is camptothecin or 9-nitrocamptothecin or other derivatives of camptothecin or triiodothyronine or tetraiodothyroxine.
6. The method of claim 1 or 2, wherein the second liquid contains the pharmaceutical active in solution.
7. The method of claim 1 or 2, wherein the second liquid contains the pharmaceutical active as solid particles suspended therein.
8. The method of claim 1, wherein e) and f) are repeated.
9. The method of claim 8, wherein a) and b), c) and d), andor g) and h) are repeated.
10. The method of claim 1 or 2, wherein the bulk material comprises one or more pharmaceutical excipients.
11. The method of claim 10, wherein the bulk material further comprises a binder.
12. The method of claim 10, wherein the bulk material further comprises a gelation agent.
13. The method of claim 12, wherein the gelation agent comprises a hydrophilic polymer.
14. The method of claim 13, wherein the hydrophilic polymer is selected from the group consisting of hydroxypropyl methylcellulose, polyvinyl alcohol, polyethylene glycol, polyethylene oxide, carbopol, hydrophilic silica gel, xanthan gum, gellan gum, locust bean gum, acrylic acid polymer, gelatin, sodium carboxymethyl cellulose, methylcellulose, guar gum, sodium alginate, polyethylene-polypropylene copolymer, corn starch, polyvinyl pyrrolidone, and polyoxyethylene alkyl ether.
15. The method of claim 10, wherein the shell region comprises a substance that controls the release of pharmaceutical active from the dosage form.
16. The method of claim 10 further comprising a capsule that completely surrounds the shell.
17. The method of claim 10, wherein the shell region further comprises adhesive or plasticizer.
18. The method of claim 10, wherein the bulk material comprises solid particles of an adhesive.
19. The method of claim 10, wherein the core region further comprises a steric hindrant, suspending agent or both.
20. The method of claim 10, wherein the dosage form provides a delayed release of pharmaceutical active.
21. The method of claim 1 or 2, wherein the transitional region comprises multiple regions of unbound or partially bound powder, which has not been printed upon, surrounding the core region.
22. The method of claim 1 or 2, wherein adjacent layers of the shell region are bound to each other.
23. The method of claim 10, wherein the shell region further comprises a non-toxic pharmaceutical active.
24. The method of claim 23, wherein the non-toxic pharmaceutical active is complementary in action to the pharmaceutical active in the core region.
25. The method of claim 10, wherein the shell region comprises an anti-emetic drug, taste-masking active, sugar, or additive to increase the physical integrity and reduce friability of the dosage form.
26. The method of claim 10, wherein the second fluid further comprises a second toxic or potent pharmaceutical active.
27. The method of claim 10, wherein the one or more predetermined locations in one layer is different than the one or more predetermined locations in another layer.