<PAGE>

                                                                   EXHIBIT 10.38

                             UNCONDITIONAL GUARANTY

In consideration of SILICON VALLEY BANK'S ("Buyer") financing to Superconductor
Technologies, Inc. ("Seller"), under the Accounts Receivable Purchase Agreement
dated as of the Effective Date (as defined therein) (the "Agreement"),
Conductus, Inc. ("Guarantor"), a Delaware corporation, unconditionally and
irrevocably guarantees payment of all amounts Seller owes Buyer and Seller's
performance of the Agreement and any other agreements between Seller and Buyer,
as amended from time to time (collectively the "Agreements"), according to their
terms.

         1.       If Seller does not perform its obligations under the
Agreements, Guarantor will immediately pay all amounts due (including, without
limitation, all principal, interest, and fees) and satisfy all Seller's
obligations under the Agreements.

         2.       These obligations are independent of Seller's obligations and
separate actions may be brought against Guarantor (whether action is brought
against Seller or whether Seller is joined in the action). Guarantor waives
benefit of any statute of limitations affecting its liability. Guarantor's
liability is not contingent on the genuineness or enforceability of the
Agreements.

         3.       Buyer may, without notice to Guarantor and without affecting
Guarantor's obligations under this Guaranty, (a) renew, extend, or otherwise
change the terms of the Agreements; (b) take security for the payment of this
Guaranty or the Agreements; (c) exchange, enforce, waive and release any
security; and (d) apply the security and direct its sale as Buyer, in its
discretion, chooses. All notices or demands by any party about this Agreement or
any other related agreement must be in writing and be personally delivered or
sent by an overnight delivery service, by certified mail, postage prepaid,
return receipt requested.

         4.       Guarantor waives:

                  a)       Any right to require Buyer to (i) proceed against
                           Seller or any other person; (ii) proceed against or
                           exhaust any security or (iii) pursue any other
                           remedy. Buyer may exercise or not exercise any right
                           or remedy it has against Seller or any security it
                           holds (including the right to foreclose by judicial
                           or nonjudicial sale) without affecting Guarantor's
                           liability.

                  b)       Any defenses from disability or other defense of
                           Seller or from the cessation of Sellers liabilities.

                  c)       Any setoff, defense or counterclaim against Buyer.

                  d)       Any defense from the absence, impairment or loss of
                           any right of reimbursement or subrogation or any
                           other rights against Seller. Until Seller's
                           obligations to Buyer have been paid, Guarantor has no
                           right of subrogation or reimbursement or other rights
                           against Seller.

                  e)       Any right to enforce any remedy that Buyer has
                           against Seller.

                  f)       Any rights to participate in any security held by
                           Buyer.

                  g)       Any demands for performance, notices of
                           nonperformance or of new or additional indebtedness.
                           Guarantor is responsible for being and keeping itself
                           informed of Seller's financial condition. Unless
                           Guarantor requests particular information, Buyer has
                           no duty to provide information to Guarantor.

                                        1

<PAGE>

                  (h)      The benefits of California Civil Code sections 2809,
                           2810, 2819, 2845, 2847, 2848, 2849, 2850, 2899 and
                           3433.

         5.       Guarantor acknowledges that, to the extent Guarantor has or
may have rights of subrogation or reimbursement against Seller for claims
arising out of this Guaranty, those rights may be impaired or destroyed if Buyer
elects to proceed against any real property security of Seller by non-judicial
foreclosure. That impairment or destruction could, under certain judicial cases
and based on equitable principles of estoppel, give rise to a defense by
Guarantor against its obligations under this Guaranty. Guarantor waives that
defense and any others arising from Buyer's election to pursue non-judicial
foreclosure. Without limiting the generality of the foregoing, Guarantor waives
all benefits and defenses under California Code of Civil Procedure Sections
580a, 580b, 580d and 726, to the extent they apply.

         6.       If Seller becomes insolvent or is adjudicated bankrupt or
files a petition for reorganization, or similar relief under the United States
Bankruptcy Code, or if a petition is filed against Seller and/or any obligation
under the Agreements is terminated or rejected or any obligation of Seller is
modified or if Seller's obligations are avoided Guarantor's liability will not
be affected and its liability will continue. If Buyer must return any payment
because of the insolvency, bankruptcy or reorganization of Seller, Guarantor or
any other guarantor this Guaranty will remain effective or be reinstated

         7.       Guarantor subordinates any indebtedness of Seller it holds to
Buyer; and Guarantor will collect, enforce and receive payments as Buyer's
trustee and will pay Buyer those payments without reducing or affecting its
liability under this Guaranty.

         8.       Guarantor will pay Buyer's reasonable attorneys' fees and
other costs and expenses incurred enforcing this Guaranty. This Guaranty may not
be waived, revoked or amended without Buyer's prior written consent. If any
provision of this Guaranty is unenforceable, all other provisions remain
effective. This Guaranty is the entire agreement among the parties about this
Guaranty. No prior dealings, no usage of trade, and no parol or extrinsic
evidence may supplement or vary this Guaranty. Buyer may assign this Guaranty
without in any way affecting Guarantor's liability under it. This Guaranty shall
inure to the benefit of Buyer and its successors and assigns. This Guaranty is
in addition to the guaranties of any other guarantors and any and all other
guaranties of Seller's indebtedness or liabilities to Buyer. Guarantor may not
assign this Agreement or any rights under it without Buyer's prior written
consent, which may be granted or withheld in Buyer's discretion.

         9.       Guarantor represents and warrants that (i) it has taken all
action necessary authorize execute, deliver and perform this Guaranty, (ii)
execution, delivery and performance of this Guaranty do not conflict with any
organizational documents or agreements to which it is party and (iii) this
Guaranty is a valid and binding obligation, enforceable against Guarantor
according to its terms.

         10.      Guarantor will do all of the following:

                           10.1 Maintain its legal existence, remain in good
standing in the state of its formation, and continue to qualify in each
jurisdiction in which the failure to qualify could have a material adverse
effect on the financial condition, operations or business. Maintain all
licenses, approvals and agreements, the loss of which could have a material
adverse effect on its financial condition, operations or business.

                           10.2 Comply with all statutes and regulations if
non-compliance could adversely affect its financial condition, operations or
business.

                           10.3 Execute other instruments and take action Buyer
reasonably requests to effect the purposes of this Agreement.

                                        2

<PAGE>

                           10.4 Deliver to Buyer complete and current financial
information and other information about Guarantor as Buyer may reasonably
request.

         11.      This Guaranty is governed by California law, without regard to
conflicts of laws. GUARANTOR WAIVES ITS RIGHT TO A JURY TRIAL OF ANY ACTION
ARISING OUT OF THIS GUARANTY, INCLUDING CONTRACT CLAIMS, TORT CLAIMS, AND ALL
OTHER CLAIMS. Guarantor submits to the exclusive jurisdiction of the state and
federal courts in Santa Clara, California.

Date ___________________                     CONDUCTUS, INC.

                                             By:________________________________

                                             Title:_____________________________

                                        3